Android学习笔记

BitmapFactory.Options options = new BitmapFactory.Options();
//options.outWidth = 800;   //图片宽度
//options.outHeight = 600   //图片高度
options.inJustDecodeBounds = false;     //设为true，那么BitmapFactory并不会真的返回一个Bitmap，它仅仅会把它的宽，高取回来给你
options.inSampleSize = 2;   //大于1时，图像高、宽分别以2的inSampleSize次方分之一缩小
options.inPreferredConfig = Bitmap.Config.ARGB_4444;    //设置图片的采样率
options.inScaled = true;    //是否需要放缩位图

Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options);

int maxMemory = (int) Runtime.getRuntime().maxMemory(); //获取应用的可用内存大小
int cacheSize = maxMemory / 8;  //定义缓存的总容量大小，此处为内存容量的 1/8
//创建LruCache，定义key和value的类型。重写计算缓存单位大小的sizeOf方法
LruCache<String, Bitmap> imgCache = new LruCache<String, Bitmap>(cacheSize) {
        @Override
        protected int sizeOf(String key, Bitmap value) {
            return value.getRowBytes() * value.getHeight();
        }
    };

imgCache.put("TEST_IMG", bitmap);   //存储到缓存
bitmap = imgCache.get("TEST_IMG");  //从缓存中取出

compile 'com.jakewharton:disklrucache:2.0.2'

import com.jakewharton.disklrucache.DiskLruCache;

//
try {
    DiskLruCache.Editor editor = diskLruCache.edit("testimg");
    if(editor != null) {
        OutputStream outputStream = editor.newOutputStream(0);
        outputStream.write(data);
        //写入之后必须进行commit操作
        outputStream.flush();
        editor.commit();
    }

} catch (IOException e) {
    e.printStackTrace();
}

try {
    //获取缓存的snapshot，参数为key
    DiskLruCache.Snapshot snapshot = diskLruCache.get("testimg");
    if(snapshot!=null){
        //snapshot中获取缓存的数据，参数为单个节点的编号
        Bitmap bitmap = BitmapFactory.decodeStream(snapshot.getInputStream(0));
        return bitmap;
    }
} catch (IOException e) {
    e.printStackTrace();
}

public final static String BROADCAST_EXIT = "BROADCAST_EXIT";

public class AppContext extends Application {
    public LocalBroadcastManager localBroadcastManager;

    @Override
    public void onCreate() {
        localBroadcastManager = LocalBroadcastManager.getInstance(this);
    }
}

public class MainpageActivity extends AppCompatActivity {
    。。。
    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            finish();
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        。。。
        appContext.localBroadcastManager.registerReceiver(broadcastReceiver, new IntentFilter(StaticValues.BROADCAST_EXIT));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        appContext.localBroadcastManager.unregisterReceiver(broadcastReceiver);
    }

}

//退出App,关闭所有activity
appContext.localBroadcastManager.sendBroadcast(new Intent(StaticValues.BROADCAST_EXIT));

InputStream is = getResources().openRawResource(R.id.filename);  

AssetManager am = null;  
am = getAssets();  
InputStream is = am.open("filename");

package com.viator42.ugo.utils;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.annotation.VisibleForTesting;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import com.bumptech.glide.Glide;
import com.bumptech.glide.GlideBuilder;
import java.io.File;
import java.lang.Deprecated;
import java.lang.String;

/**
* The entry point for interacting with Glide for Applications
*
* <p>Includes all generated APIs from all
* {@link com.bumptech.glide.annotation.GlideExtension}s in source and dependent libraries.
*
* <p>This class is generated and should not be modified
* @see Glide
*/
public final class GlideApp {
    private GlideApp() {
    }

    /**
    * @see Glide#getPhotoCacheDir(Context)
    */
    @Nullable
    public static File getPhotoCacheDir(@NonNull Context context) {
        return Glide.getPhotoCacheDir(context);
    }

    /**
    * @see Glide#getPhotoCacheDir(Context, String)
    */
    @Nullable
    public static File getPhotoCacheDir(@NonNull Context context, @NonNull String string) {
        return Glide.getPhotoCacheDir(context, string);
    }

    /**
    * @see Glide#get(Context)
    */
    @NonNull
    public static Glide get(@NonNull Context context) {
        return Glide.get(context);
    }

    /**
    * @see Glide#init(Glide)
    */
    @Deprecated
    @VisibleForTesting
    @SuppressLint("VisibleForTests")
    public static void init(Glide glide) {
        Glide.init(glide);
    }

    /**
    * @see Glide#init(Context, GlideBuilder)
    */
    @VisibleForTesting
    @SuppressLint("VisibleForTests")
    public static void init(@NonNull Context context, @NonNull GlideBuilder builder) {
        Glide.init(context, builder);
    }

    /**
    * @see Glide#tearDown()
    */
    @VisibleForTesting
    @SuppressLint("VisibleForTests")
    public static void tearDown() {
        Glide.tearDown();
    }

    /**
    * @see Glide#with(Context)
    */
    @NonNull
    public static GlideRequests with(@NonNull Context context) {
        return (GlideRequests) Glide.with(context);
    }

    /**
    * @see Glide#with(Activity)
    */
    @NonNull
    public static GlideRequests with(@NonNull Activity activity) {
        return (GlideRequests) Glide.with(activity);
    }

    /**
    * @see Glide#with(FragmentActivity)
    */
    @NonNull
    public static GlideRequests with(@NonNull FragmentActivity activity) {
        return (GlideRequests) Glide.with(activity);
    }

    /**
    * @see Glide#with(Fragment)
    */
    @NonNull
    public static GlideRequests with(@NonNull Fragment fragment) {
        return (GlideRequests) Glide.with(fragment);
    }

    /**
    * @see Glide#with(Fragment)
    */
    @Deprecated
    @NonNull
    public static GlideRequests with(@NonNull android.app.Fragment fragment) {
        return (GlideRequests) Glide.with(fragment);
    }

    /**
    * @see Glide#with(View)
    */
    @NonNull
    public static GlideRequests with(@NonNull View view) {
        return (GlideRequests) Glide.with(view);
    }
}

GlideApp.with(context)
    .load(url)
    .centerCrop()
    .into(imgView);

<Button
android:id="@+id/btn1" />
Button btn1 = findViewById(R.id.btn1);

import android.util.Log;
Log.v(“log title”, “value");

//获取SharedPreferences实例     第一个参数是名称, 第二个是作用域
SharedPreferences ref = getSharedPreferences("user", Context.MODE_PRIVATE);
//获取数据,参数分别为key值和默认值(未取到值时的返回值)
int id = ref.getInt("id", 0);
ref.getString("username", "")

//向SharedPreferences存储数据
SharedPreferences ref = activity.getSharedPreferences("user", Context.MODE_PRIVATE);
//获取editor对象
SharedPreferences.Editor editor = ref.edit();
//赋值
editor.putInt("id", 1);
editor.putString("tel", “1234567890");
//完成后提交修改
editor.commit();

public class StatisticFragment extends Fragment {
    private OnFragmentInteractionListener mListener;
    private AppContext context;
    private Store store;

    private TextView productCountTextView;

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @return A new instance of fragment StatisticFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static StatisticFragment newInstance(String param1, String param2) {
        StatisticFragment fragment = new StatisticFragment();
        Bundle args = new Bundle();

        fragment.setArguments(args);
        return fragment;
    }

    public StatisticFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        context = (AppContext) getActivity().getApplicationContext();
        store = context.getStore();

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_statistic, container, false);

        productCountTextView = (TextView) view.findViewById(R.id.product_count);
        
        return view;
    }
}

private FragmentManager manager;
private FragmentTransaction transaction;

manager = getFragmentManager();
transaction = manager.beginTransaction();
transaction.replace(R.id.content, fragment );
transaction.commit();

fragment1 = new Fragment1();
Bundle bundle = new Bundle();
bundle.putParcelable("data", model01);

fragment1.setArguments(bundle);

transaction = manager.beginTransaction();
transaction.replace(R.id.content, fragment1);
transaction.commit();

public static Fragment1 newInstance(Model01 model01) {
    Fragment1 fragment = new Fragment1();
    Bundle args = new Bundle();
    args.putParcelable("data", model01);
    fragment.setArguments(args);
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    if (getArguments() != null) {
        model01 = getArguments().getParcelable("data");
    }
}

FragmentManager manager = getFragmentManager();
Fragment1 fragment1 = (Fragment1) manager.findFragmentById(R.id.content);

FragmentTransaction transaction;
transaction = manager.beginTransaction();
transaction.setCustomAnimations(android.R.anim.fade_in, R.anim.slide_out);  //可以为fragment切换设置转场动画
transaction.replace(R.id.content_frame, fragment)
transaction.commit();

transaction.hide(currentFragment);
if(mainpageFragment == null) {
    mainpageFragment = new MainpageFragment();
    transaction.add(R.id.content, mainpageFragment);
}
else {
    transaction.show(mainpageFragment);
}
currentFragment = mainpageFragment;
transaction.commit();

private ArrayList<String> paymethodList;
private ListView payMethodListView;

payMethodListView = (ListView) view.findViewById(R.id.pay_method_list);

paymethodList = new ArrayList<String>();
        paymethodList.add("支付宝");
        paymethodList.add("信用卡1");
        paymethodList.add("信用卡2");

ArrayAdapter adapter = new ArrayAdapter(context, android.R.layout.simple_list_item_1, paymethodList);
        payMethodListView.setAdapter(adapter);
        payMethodListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                payMethod = paymethodList.get(position);
                setPayConfirmMode();
            }
        });

listview=new ListView(this);

//android.R.layout.simple_list_item_single_choice设置ListView项目条带单选按钮

listview.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_single_choice,getData()));

listview.setChoiceMode(ListView.CHOICE_MODE_SINGLE);//如果不使用这个设置，选项中的radiobutton无法响应选中事件

listview.setItemChecked(2, true);

payMethodListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                listview.setItemChecked(position, true);
            }
        });

adapter.add() 或者addAll()添加元素
adapter.notifyDataSetChanged();      //通知listview数据改变

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">

<TextView
android:layout_width="100dp"
android:layout_height="50dp"
android:id="@+id/name" />

<TextView
android:layout_width="100dp"
android:layout_height="50dp"
android:id="@+id/price" />

<TextView
android:layout_width="100dp"
android:layout_height="50dp"
android:id="@+id/address" />
</LinearLayout>

public class ContentAdaper extends BaseAdapter {
    //填充数据的List
    List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();

    //上下文
    private Context context;

    //用来导入布局
    private LayoutInflater inflater = null;

    //构造器
    public ContentAdaper(List<Map<String, Object>> list, Context context) {
        this.context = context;
        this.list = list;
        inflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return list.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return list.get(arg0);
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    //核心部分，返回Listview视图
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        ViewHolder holder = null;

        if (convertView == null) {
            holder = new ViewHolder();
            convertView = inflater.inflate(R.layout.layout, null);
            holder.name = (TextView) convertView.findViewById(R.id.name);
            holder.price = (TextView) convertView.findViewById(R.id.price);
            holder.address = (TextView) convertView.findViewById(R.id.address);
            //为view设置标签
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.name.setText(list.get(position).get("name").toString());
        holder.price.setText(list.get(position).get("price").toString());
        holder.address.setText(list.get(position).get("address").toString());

        return convertView;
    }

    static class ViewHolder {
        TextView name;
        TextView price;
        TextView address;
    }
}

List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
Map item1 = new HashMap();
item1.put("name", "Name1");
item1.put("price", "450")
item1.put("address", "address 101");
data.add(item1);
ContentAdaper adaper = new ContentAdaper(data, this);
listView.setAdapter(adaper);

position

orderlistView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

        }
    });

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return (long)list.get(position).get("id");

}

mListView.scrollTo(x, y)

//设置默认滚动到顶部
scrollView.post(new Runnable() {

@Override
public void run() {
    // TODO Auto-generated method stub
    scrollView.fullScroll(ScrollView.FOCUS_UP);
}
});

//设置默认滚动到底部
scrollView.post(new Runnable() {

@Override
public void run() {
    // TODO Auto-generated method stub
    scrollView.fullScroll(ScrollView.FOCUS_DOWN);
}
});

View中有EditText的时候页面加载焦点会自动放到第一个EditText上,取消方法是在跟节点添加以下属性

android:focusable="true"
android:focusableInTouchMode="true" 

List listData = new ArrayList<Map<String,Object>>();

Map line = new HashMap();
line.put("id", 1);
line.put("name", "beijing");
listData.add(line);

// 参数含义, context, 列表数据, 列表项布局, 显示的value名称, 名称对应的xml布局id
SimpleAdapter adapter = new SimpleAdapter(this, listData, R.layout.spinner_item, new String[] {"name"}, new int[] {R.id.name});
provinceSpinner.setAdapter(adapter);

provinceSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
            Toast.makeText(RegisterActivity.this, ((Map)provinceSpinner.getItemAtPosition(i)).get("id").toString(), Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> adapterView) {

        }
    });

public class AppContext extends Application
{
    private User user;
    private Store store;

    @Override
    public void onCreate() {
        super.onCreate();

    }
}

<application
    android:name=".AppContext" >

AppContext context =  (AppContext)activity.getApplication();

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

import android.os.Handler;
import android.os.Message;

private String imgUrl = "http://image_url";
private final int IS_END = 1;
private ProgressDialog dialog;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    img = (ImageView)findViewById(R.id.img);
    loadImgBtn = (Button)findViewById(R.id.load_image);
    loadImgBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        	//新建一个网络访问的线程.
            new Thread(new MyThread()).start();
            dialog.show();

        }
    });

    dialog = new ProgressDialog(this);
    dialog.setTitle("提示");
    dialog.setMessage("正在下载,请稍后....");
    dialog.setCancelable(false);

}

public Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg)
    {
    	//获取Message消息
        byte[] data = (byte[])msg.obj;
        Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
        img.setImageBitmap(bitmap);

        if(msg.what == IS_END)
        {
            dialog.dismiss();
        }

    }
};


public class MyThread implements Runnable
{

    @Override
    public void run() {
        HttpClient httpClient = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(imgUrl);
        HttpResponse response = null;
        try{
            response = httpClient.execute(httpGet);
            if(response.getStatusLine().getStatusCode() == 200)
            {
                byte[] data = EntityUtils.toByteArray(response.getEntity());
                //Message.obtain()方法是从消息池中获取消息对象.
                Message message = Message.obtain();
                message.obj = data;
                message.what = IS_END;
                //发送Message消息
                handler.sendMessage(message);

            }

        } catch (Exception e)
        {
            e.printStackTrace();
        }


    }
}

keytool -list -v -keystore ~/.android/debug.keystore

ArrayList<Map<String, Object>> result= new ArrayList<Map<String, Object>>();
Map province = new HashMap();
province.put("id", jsonObject.getString("code"));
province.put("name", jsonObject.getString("name"));
result.add(province);

provinceSpinner = (Spinner)findViewById(R.id.province);

SimpleAdapter adapter = new SimpleAdapter
    NewStoreActivity.this, result, R.layout.spinner_item, new String[] {"name"}, new int[] {R.id.alias});
provinceSpinner.setAdapter(adapter);
provinceSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
        String code = ((Map) provinceSpinner.getItemAtPosition(i)).get("id").toString();
        new GetCityTask().execute(new Integer(code));

    }
    @Override
    public void onNothingSelected(AdapterView<?> adapterView) {

    }
});

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent"
    android:orientation="horizontal">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="25dp"
        android:id="@+id/alias"
        android:gravity="center" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent"
    android:orientation="horizontal">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="25dp"
        android:id="@+id/name"
        android:gravity="center" />
</LinearLayout>

/Users/viator42/Library/Android/sdk/tools/mksdcard

mksdcard -l <label> <size> <file>

iconImageBtn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        //打开相册
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        intent.putExtra("crop", "true");
        intent.putExtra("return-data", true);

        startActivityForResult(intent, 1000);
    }
});

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1000 && resultCode == RESULT_OK) {
        if(data != null)
        {
            ContentResolver resolver = getContentResolver();
            Uri originalUri = data.getData();
            try {
                MediaStore.Images.Media.getBitmap(resolver, originalUri);

            } catch (IOException e) {
                e.printStackTrace();
            }
            if (logoBitmap != null)
            {
                //获取Bitmap
                iconImageBtn.setImageBitmap(logoBitmap);

            }

        }
        else
        {
            Toast.makeText(activity.getApplicationContext(), "图片读取失败", Toast.LENGTH_SHORT).show();
        }
    }

    super.onActivityResult(requestCode, resultCode, data);

}

private File sdcardTempFile = new File("/mnt/sdcard/", "tmp_pic_" + SystemClock.currentThreadTimeMillis() + ".jpg");

iconImageBtn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        //打开相册
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        intent.putExtra("crop", "true");
        intent.putExtra("aspectX", 1);// 裁剪框比例
        intent.putExtra("aspectY", 1);
        intent.putExtra("outputX", StaticValues.ICON_WIDTH);// 输出图片大小
        intent.putExtra("outputY", StaticValues.ICON_HEIGHT);
        intent.putExtra("return-data", false);// 不返回图片数据(必须)
        intent.putExtra("output", Uri.fromFile(sdcardTempFile));

        startActivityForResult(intent, 1000);
        }
    });

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 1000 && resultCode == RESULT_OK) {
        if(data != null)
        {
            logoBitmap = BitmapFactory.decodeFile(sdcardTempFile.getAbsolutePath());
            if (logoBitmap != null)
            {
                iconImageBtn.setImageBitmap(logoBitmap);
            }s
        }
        else
        {
            Toast.makeText(activity.getApplicationContext(), "图片读取失败", Toast.LENGTH_SHORT).show();
        }
    }
    super.onActivityResult(requestCode, resultCode, data);
}

/**
 * 图片进行压缩处理,宽度固定,高度自动适配
 * @param bm
 *
 * @return
 */
public static Bitmap zoomImg(Bitmap bm){
    // 获得图片的宽高
    int width = bm.getWidth();
    int height = bm.getHeight();

    if(width > 0 && height > 0)
    {
        if(width <= StaticValues.WIDTH_LIMIT)
        {
            //原图小于规定尺寸的不用缩放
            return bm;
        }
        else
        {
            int newWidth = StaticValues.WIDTH_LIMIT;
            int newHeight = (int)((newWidth * height) / width);
            // 计算缩放比例
            float scaleWidth = ((float) newWidth) / width;
            float scaleHeight = ((float) newHeight) / height;

            // 取得想要缩放的matrix参数
            Matrix matrix = new Matrix();
            matrix.postScale(scaleWidth, scaleHeight);
            // 得到新的图片
            Bitmap newbm = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, true);
            return newbm;
        }
    }
    else
    {
        return bm;

    }
}

Intent intent = new Intent("com.android.camera.action.CROP");
intent.setDataAndType(imageUri, "image/*");
intent.putExtra("crop", "true");
intent.putExtra("aspectX", 1);
intent.putExtra("aspectY", 1);
intent.putExtra("outputX", StaticValues.ICON_WIDTH);
intent.putExtra("outputY", StaticValues.ICON_HEIGHT);
intent.putExtra("scale", true);
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
intent.putExtra("return-data", false);
intent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());
intent.putExtra("noFaceDetection", true); // no face detection
startActivityForResult(intent, StaticValues.IMAGE_CROP);

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if(requestCode == StaticValues.IMAGE_CROP && resultCode == RESULT_OK)
    {
        //裁剪
        if(imageUri != null){
            logoBitmap = decodeUriAsBitmap(imageUri);//decode bitmap
            iconImageBtn.setImageBitmap(logoBitmap);
        }
        else
        {
            Toast.makeText(NewStoreActivity.this, "图片裁剪失败", Toast.LENGTH_SHORT).show();
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="im.supai.supaimarketing" >
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
...
</manifest>

public class NewStoreActivity extends BaseAccivity implements LocationListener {
    
    //位置相关
    @Override
    public void onLocationChanged(Location location) {
        latitude = location.getLatitude();
        longitude = location.getLongitude();
    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {
    }

    @Override
    public void onProviderEnabled(String s) {
    }

    @Override
    public void onProviderDisabled(String s) {
    }
}

LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, (android.location.LocationListener) this);

itemBtn.setAdjustViewBounds(true);
itemBtn.setMaxWidth(100);

把view的宽度设置为0dp同时设置weight属性.

android:layout_width="0dp"
android:layout_weight="1"

<AutoCompleteTextView
android:id="@+id/search_bar" />

private AutoCompleteTextView searchEditText;
searchEditText = (AutoCompleteTextView) findViewById(R.id.search_bar);

String[] ary = new String[]{"aaa", "bbb"};  //定义候选词列表,可以使用字符串数组或者ArrayList

//定义adaper
ArrayAdapter<String> searchEditAdapter=new ArrayAdapter<String>(this, 
    android.R.layout.simple_dropdown_item_1line, context.searchList);
searchEditText.setAdapter(searchEditAdapter);

android:theme="@style/AppTheme.NoActionBar"

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" >

        <!--自定义控件-->
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="自定义控件" />

    </android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //定义和初始化ToolBar
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        toolbar.setNavigationIcon(R.mipmap.ic_launcher);//设置导航栏图标
        toolbar.setLogo(R.mipmap.ic_launcher);//设置app logo
        toolbar.setTitle("Title");//设置主标题
        toolbar.setSubtitle("Subtitle");//设置子标题

    }
}

<menu xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/item_1"
        android:showAsAction="never"
        android:icon="@drawable/ic_plus_white_24dp"
        android:title="ITEM_1"
        />
    <item
        android:id="@+id/item_2"
        android:title="ITEM_2"
        />
</menu>

public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    getMenuInflater().inflate(R.menu.mainpage_menu, menu);
    return true;
}

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId())
    {
        case R.id.item_1:
            Toast.makeText(MainActivity.this, "Menu item 1", Toast.LENGTH_SHORT).show();
            break;

        case R.id.item_2:
            Toast.makeText(MainActivity.this, "Menu item 2", Toast.LENGTH_SHORT).show();
            break;

        case R.id.item_3:
            Toast.makeText(MainActivity.this, "Menu item 3", Toast.LENGTH_SHORT).show();
            break;

    }
    return super.onOptionsItemSelected(item);
}

//动态调整菜单,比如说控制菜单项是否显示
public boolean onPrepareOptionsMenu(Menu menu) {
    MenuItem itemAddressSetDefault = menu.findItem(R.id.action_address_set_default);
    itemAddressSetDefault.setVisible(false);

    return super.onPrepareOptionsMenu(menu);
}

//true 说明这个timer以daemon方式运行（优先级低，程序结束timer也自动结束）   
java.util.Timer timer = new java.util.Timer(true);  
  
TimerTask task = new TimerTask() {  
   public void run() {  
   //每次需要执行的代码放到这里面。     
   }     
};  
  
//以下是几种调度task的方法：  
  
//time为Date类型：在指定时间执行一次。  
timer.schedule(task, time);  
  
//firstTime为Date类型,period为long，表示从firstTime时刻开始，每隔period毫秒执行一次。  
timer.schedule(task, firstTime, period);     
  
//delay 为long类型：从现在起过delay毫秒执行一次。  
timer.schedule(task, delay);  
  
//delay为long,period为long：从现在起过delay毫秒以后，每隔period毫秒执行一次。  
timer.schedule(task, delay, period);  

import android.app.Activity;  
import android.os.Bundle;  
import android.os.Handler;  
import android.os.Message;  
  
import java.util.Timer;  
import java.util.TimerTask;  
  
public class TimerTaskActivity extends Activity {  
  
    private Timer mTimer;  
  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        // init timer  
        mTimer = new Timer();  
        // start timer task  
        setTimerTask();  
    }  
  
    @Override  
    protected void onDestroy() {  
        super.onDestroy();  
        // cancel timer  
        mTimer.cancel();  
    }  
  
    private void setTimerTask() {  
        mTimer.schedule(new TimerTask() {  
            @Override  
            public void run() {  
                Message message = new Message();  
                message.what = 1;  
                doActionHandler.sendMessage(message);  
            }  
        }, 1000, 1000/* 表示1000毫秒之後，每隔1000毫秒執行一次 */);  
    }  
  
    /** 
     * do some action 
     */  
    private Handler doActionHandler = new Handler() {  
        @Override  
        public void handleMessage(Message msg) {  
            super.handleMessage(msg);  
            int msgId = msg.what;  
            switch (msgId) {  
                case 1:  
                    // do some action  
                    break;  
                default:  
                    break;  
            }  
        }  
    };  
}  

msgTextView.setText(String.valueOf(costomWidget.getMeasuredWidth()) + "  " + String.valueOf(costomWidget.getMeasuredHeight()));

BitmapFactory.Options options = new BitmapFactory.Options();
        options2.inPreferredConfig = Bitmap.Config.RGB_565;
bm = BitmapFactory.decodeFile("filepath/file.jpg", options);

public class MainpageBannerViewPagerAdapter extends PagerAdapter {
    private Context context;
    private ArrayList<SimpleDraweeView> imageViews;

    public MainpageBannerViewPagerAdapter(Context context, ArrayList<SimpleDraweeView> imageViews) {
        this.context = context;
        this.imageViews = imageViews;
    }

    @Override
    public int getCount() {
        return imageViews.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public ImageView instantiateItem(ViewGroup container, int position) {
        SimpleDraweeView imageView = imageViews.get(position);
        container.addView(imageView);
        return imageView;
    }

}

viewPager.setAdapter(goodsViewPagerAdapter);

public class Calculator {
    public int add(int one, int another) {
        // 为了简单起见，暂不考虑溢出等情况。
        return one + another;
    }

    public int multiply(int one, int another) {
        // 为了简单起见，暂不考虑溢出等情况。
        return one * another;
    }
}

public class CalculatorTest {
    Calculator mCalculator;

    @Before
    public void setup() {
        mCalculator = new Calculator();
    }

    @Test
    public void testAdd() throws Exception {
        int sum = mCalculator.add(1, 2);
        assertEquals(3, sum);  //为了简洁，往往会static import Assert里面的所有方法。
    }

    @Test
    public void testMultiply() throws Exception {
        int product = mCalculator.multiply(2, 4);
        assertEquals(8, product);
    }

}

adb shell dumpsys meminfo [package name]

ActivityManager activityManager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);

获取堆内存大小(单位M)
activityManager.getMemoryClass()
activityManager.getLargeMemoryClass()

public abstract class EndlessRecyclerOnScrollListener extends RecyclerView.OnScrollListener {
    public static String TAG = EndlessRecyclerOnScrollListener.class.getSimpleName();

    private int previousTotal = 0; // The total number of items in the dataset after the last load
    private boolean loading = true; // True if we are still waiting for the last set of data to load.
    private int visibleThreshold = 5; // The minimum amount of items to have below your current scroll position before loading more.
    int firstVisibleItem, visibleItemCount, totalItemCount;

    private int current_page = 1;

    private GridLayoutManager layoutManager;

    public EndlessRecyclerOnScrollListener(GridLayoutManager layoutManager) {
        this.layoutManager = layoutManager;
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);

        visibleItemCount = recyclerView.getChildCount();
        totalItemCount = layoutManager.getItemCount();
        firstVisibleItem = layoutManager.findFirstVisibleItemPosition();

        if (loading) {
            if (totalItemCount > previousTotal) {
                loading = false;
                previousTotal = totalItemCount;
            }
        }
        if (!loading && (totalItemCount - visibleItemCount)
                <= (firstVisibleItem + visibleThreshold)) {
            // End has been reached

            // Do something
            current_page++;

            onLoadMore(current_page);

            loading = true;
        }
    }

    public abstract void onLoadMore(int current_page);
}

public abstract class EndlessGridRecyclerOnScrollListener extends
        RecyclerView.OnScrollListener {

    private int previousTotal = 0;
    private boolean loading = true;
    int firstVisibleItem, visibleItemCount, totalItemCount;

    private int currentPage = 1;

    private GridLayoutManager gridLayoutManager;

    public EndlessGridRecyclerOnScrollListener(
            GridLayoutManager gridLayoutManager) {
        this.gridLayoutManager = gridLayoutManager;
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);

        CommonUtils.log(String.valueOf(dx) + " " + String.valueOf(dy) );

        visibleItemCount = recyclerView.getChildCount();
        totalItemCount = gridLayoutManager.getItemCount();
        firstVisibleItem = gridLayoutManager.findFirstVisibleItemPosition();


        if (loading) {
            if (totalItemCount > previousTotal) {
                loading = false;
                previousTotal = totalItemCount;
            }
        }
        if (!loading && (totalItemCount - visibleItemCount) <= firstVisibleItem) {
            currentPage++;
            onLoadMore(currentPage);
            loading = true;
        }
    }

    public abstract void onLoadMore(int currentPage);
}

listView.addOnScrollListener(new EndlessGridRecyclerOnScrollListener(layoutManager) {
    @Override
    public void onLoadMore(int currentPage) {
        loadPage();
    }
});

<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior=    "@string/appbar_scrolling_view_behavior"
    tools:context=".module.branddetail.BrandDetailActivity"
    tools:showIn="@layout/activity_brand_detail"
    android:id="@+id/scroll_view">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/brand_goods_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:nestedScrollingEnabled="false"
        />

</android.support.v4.widget.NestedScrollView>

public abstract class EndlessParentScrollListener implements NestedScrollView.OnScrollChangeListener {
    // The current offset index of data you have loaded
    private int currentPage = 0;
    // The total number of items in the dataset after the last load
    private int previousTotalItemCount = 0;
    // True if we are still waiting for the last set of data to load.
    private boolean loading = true;
    // Sets the starting page index
    private int startingPageIndex = 0;
    // The minimum amount of pixels to have below your current scroll position
    // before loading more.
    private int visibleThresholdDistance = 300;

    GridLayoutManager mLayoutManager;

    public EndlessParentScrollListener(GridLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
    }

    @Override
    public void onScrollChange(NestedScrollView scrollView, int x, int y, int oldx, int oldy) {
        // We take the last son in the scrollview
        View view = scrollView.getChildAt(scrollView.getChildCount() - 1);
        int distanceToEnd = (view.getBottom() - (scrollView.getHeight() + scrollView.getScrollY()));

        int totalItemCount = mLayoutManager.getItemCount();
        // If the total item count is zero and the previous isn't, assume the
        // list is invalidated and should be reset back to initial state
        if (totalItemCount < previousTotalItemCount) {
            this.currentPage = this.startingPageIndex;
            this.previousTotalItemCount = totalItemCount;
            if (totalItemCount == 0) {
                this.loading = true;
            }
        }

        // If it’s still loading, we check to see if the dataset count has
        // changed, if so we conclude it has finished loading and update the current page
        // number and total item count.
        if (loading && (totalItemCount > previousTotalItemCount)) {
            loading = false;
            previousTotalItemCount = totalItemCount;
        }

        // If it isn’t currently loading, we check to see if we have breached
        // the visibleThreshold and need to reload more data.
        // If we do need to reload some more data, we execute onLoadMore to fetch the data.
        // threshold should reflect how many total columns there are too
        if (!loading && distanceToEnd <= visibleThresholdDistance) {
            currentPage++;
            onLoadMore(currentPage, totalItemCount);
            loading = true;
        }
    }

    // Defines the process for actually loading more data based on page
    public abstract void onLoadMore(int page, int totalItemsCount);
}

nestedScrollView.setOnScrollChangeListener(new EndlessParentScrollListener(gridLayoutManager) {
    @Override
    public void onLoadMore(int page, int totalItemsCount) {
        load();
    }
});

dependencies {
implementation 'com.jakewharton:butterknife:8.8.1'
annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'
}

//声明view的时候添加@InjectView注解
@BindView(R.id.ok_btn) //控件对应的ID
Button mBtn;

@BindView(R.id.title_text)
TextView mTitleTextView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);

    //ButterKnife初始化
    ButterKnife.inject(this);

    //这样之后就可以直接使用变量了
    mTitleTextView.setText("test");
}

public class FancyFragment extends Fragment {
@BindView(R.id.button1) Button button1;
@BindView(R.id.button2) Button button2;

@Override View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fancy_fragment, container, false);
    //添加root view参数
    ButterKnife.inject(this, view);
    return view;
}
}

@Override void onDestroyView() {
    super.onDestroyView();
    ButterKnife.reset(this);
}

@BindString(R.string.title) String title;
@BindDrawable(R.drawable.graphic) Drawable graphic;
@BindColor(R.color.red) int red; // int or ColorStateList field
@BindDimen(R.dimen.spacer) Float spacer;

@BindViews({ R.id.first_name, R.id.middle_name, R.id.last_name })
List<EditText> nameViews;

@OnClick(R.id.submit)
public void submit(View view) {
    // TODO submit data to server...
}

@Override
public void addView(View view, ViewGroup.LayoutParams params){
    mGlobal.addView(view, params, mDisplay, mParentWindow);
}

@Override
public void updateViewLayout(View view, ViewGroup.LayoutParams params){
    mGlobal.updateViewLayout(view, params);
}

@Override
public void removeView(View view){
    mGlobal.removeView(view, false);
}

private final ArrayList<View> mViews = new ArrayList<View>();
private final ArrayList<ViewRootImpl> mRoots = new ArrayList<ViewRootImpl>();
private final ArrayList<WindowManager.LayoutParams> mParams = new ArrayList<WindowManager.LayoutParams>();
private final ArraySet<View> mDyingViews = new ArraySet<View>();

mWindow = PolicyManager.makeNewWindow(this)；
mWindow.setCallback(this);
mWindow.setOnWindowDismissedCallback(this);
mWindow.getLayoutInflater().setPrivateFactory(this);

public Window makeNewWindow(Context context){
    return new PhoneWindow(context);
}

public void setContentView(int layoutResID){
    getWindow().setContentView(layoutResID);
    initWindowDecorActionBar();
}

public void setContentView(int layoutResID){
mWindow.setContentView(layoutResID);
}

<activity android:name=".MainActivity"
    ...
    android:windowSoftInputMode="adjustResize|stateHidden">
</activity>