Android 消息提醒NotificationManager

用来通过发生的事件提醒用户，出现一个状态条，可以手机背光闪烁，还可以发出声音或震动，当用户选择时候可以启动到app。

android.app.NotificationManager;
android.support.v4.app.NotificationCompat;

常用个方法：
cancel(int id)  取消之前显示出来的notification ,id用用来识别哪个消息。
cancel(String tag, int id) 
cancelAll() 取消所有的显示的notification

notify(int id, Notification notification)把一个notification) 展示到状态条
notify(String tag, int id, Notification notification) 

例如：

  NotificationManager manager= (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        Notification notification=new NotificationCompat.Builder(this)
                .setContentTitle("消息通知来了")
                .setContentText("消息通知的内容")
                .setWhen(System.currentTimeMillis())
                .setSmallIcon(R.mipmap.ic_launcher)
                .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher_round))
                .build();
        manager.notify(1,notification);

实例：状态栏通知条控制音乐播放

给notification添加视图并且绑定事件，PendingIntent这个是可以延时的意图，然后点击状态栏的notification中的按钮就能发送信息到广播接收器。广播接收器控制后台进程控制音乐的播放状态改变。

状态栏的notification 与服务通信---》服务控制音乐在后台的播放状态的改变。

package com.lht.liuhaitao;


import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.util.Log;
import android.view.View;
import android.view.animation.BounceInterpolator;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RemoteViews;
import android.widget.TextView;

public class MainActivity extends Activity {

    static final String TAG="MainActivity";
    private Button but;
    MusicService.MusicBinder binder=null;
    ServiceConnection connection=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            binder= (MusicService.MusicBinder) service;
            //存储为全局对象，共享给MusicBroadcastReceiver中使用
            MyApplication.musicBinder=binder;
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        but=findViewById(R.id.but_ok);
        but.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity.this,MusicService.class);
                intent.putExtra("action","play");
                startService(intent);
                bindService(intent,connection,BIND_AUTO_CREATE);
                notification();
                if(binder!=null){
                    binder.play();
                }

            }
        });
    }

    private void notification(){
        NotificationManager manager= (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        MyApplication.notificationManager=manager;//就为了让它变为全局，方便用。
        RemoteViews remoteView=  new RemoteViews(getPackageName(),R.layout.controll_music);
        Notification notification=new NotificationCompat.Builder(this)
                .setContentTitle("消息通知来了")
                .setContentText("消息通知的内容")
                .setWhen(System.currentTimeMillis())
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContent(remoteView)
                .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher_round))
                .build();

        //播放
        Intent intentPlay=new Intent(this,MusicService.class);
        intentPlay.putExtra("action","play");
        PendingIntent pendingIntent=PendingIntent.getService(this,1,intentPlay,PendingIntent.FLAG_UPDATE_CURRENT);
        remoteView.setOnClickPendingIntent(R.id.play,pendingIntent);
        //暂停
        Intent intentPause=new Intent(this,MusicService.class);
        intentPause.putExtra("action","pause");
        PendingIntent pendingIntentPause=PendingIntent.getService(this,2,intentPause,PendingIntent.FLAG_UPDATE_CURRENT);
        remoteView.setOnClickPendingIntent(R.id.pause,pendingIntentPause);


        //显示消息控件
        manager.notify(1,notification);

    }

}

controll_music.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageView
        android:id="@+id/play"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@mipmap/ic_launcher"
        android:text="播放"/>
    <ImageView
        android:background="@mipmap/ic_launcher"
        android:id="@+id/pause"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="暂停"/>
    <ImageView
        android:id="@+id/stop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@mipmap/ic_launcher"
        android:text="停止"/>
    <ImageView
        android:id="@+id/cancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@mipmap/ic_launcher"
        android:text="取消"/>
</LinearLayout>

 

 

 

package com.lht.liuhaitao;

import android.app.Service;
import android.content.Intent;
import android.content.ServiceConnection;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.MediaStore;
import android.util.Log;

import java.io.File;

public class MusicService extends Service {

    MusicBinder  binder=new MusicBinder();
    public MusicService(){
    }

    public class MusicBinder extends Binder{
        MediaPlayer player=null;
        public void play(){
            //Uri musicTableForSD = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
            //Uri uri = Uri.withAppendedPath(musicTableForSD,"/" + "音乐名字");
            //Uri uri=Uri.fromFile(new File("file:///android_assets/1.mp3"));
            if(player==null ){
                player= MediaPlayer.create(getApplication(),R.raw.a);
            }
            if(!player.isPlaying()){
                player.start();
            }
        }
        public void stop(){
            if(player!=null && player.isPlaying()){
                player.stop();
                player.stop();
                player.release();
                player=null;
            }
        }
        public void pause(){
            if( player!=null  && player.isPlaying()){
                player.pause();
            }
        }
    }

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

    @Override
    public IBinder onBind(Intent intent) {
        return binder;
    }

    @Override
    public void unbindService(ServiceConnection conn) {
        super.unbindService(conn);

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        String action=intent.getStringExtra("action");
        switch (action){
            case "play":
                binder.play();
                break;
            case "pause":
                binder.pause();
                break;
        }

        Log.e("wwww", "onStartCommand: "+action+""+binder );
        return super.onStartCommand(intent, flags, startId);
    }
}

package com.lht.liuhaitao;

import android.app.Application;
import android.app.NotificationManager;
import android.content.Context;

public class MyApplication extends Application {

    private static Context context;
    public static MusicService.MusicBinder musicBinder;
    public static NotificationManager notificationManager;

    public MyApplication(){
        context=getApplicationContext();
    }

    public static Context getContext(){
        return context;
    }

}