import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.app.NotificationCompat;
import android.view.View;
import android.widget.RemoteViews;
public class MainActivity extends AppCompatActivity {
  private static final int NO_1 = 0x1;
  int num =1;//初始通知数量为1
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
  //按钮点击事件（通知栏）
  public void show1(View v){
    NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
    builder.setSmallIcon(R.mipmap.ic_launcher);
    builder.setContentTitle("新消息");
    builder.setContentText("你有一条新的消息");
    builder.setNumber(num++);
    //设置点击通知跳转页面后，通知消失
    builder.setAutoCancel(true);
    Intent intent = new Intent(this,Main2Activity.class);
    PendingIntent pi = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
    builder.setContentIntent(pi);
    Notification notification = builder.build();
    NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(NO_1,notification);
  }
}

<?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="wrap_content"
  android:gravity="center">
  <ImageView
    android:id="@+id/iv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@mipmap/ic_launcher"/>
  <TextView
    android:id="@+id/tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:gravity="center"
    android:text="仗剑走天涯"/>
  <Button
    android:id="@+id/btn1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="播放"/>
  <Button
    android:id="@+id/btn2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="下一首"/>
</LinearLayout>

public void show2(View v){
    NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
    builder.setSmallIcon(R.mipmap.guojia);
    RemoteViews rv = new RemoteViews(getPackageName(),R.layout.message);
    rv.setTextViewText(R.id.tv,"泡沫");//修改自定义View中的歌名
    //修改自定义View中的图片(两种方法)
//    rv.setImageViewResource(R.id.iv,R.mipmap.ic_launcher);
    rv.setImageViewBitmap(R.id.iv, BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher));
    builder.setContent(rv);
    Notification notification = builder.build();
    NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(NO_2,notification);
  }