Android通知之Notification的用法剖析

来源：互联网发布：零基础学java pdf 编辑：程序博客网时间：2024/06/08 15:39

一）创建一个简单的Notification，根据谷歌官方介绍的方法，我们利用V4包里的NotificationCompat.Builder的方法来创建最好，也非常简单，主要有几个参数，setSmallIcon()是通知左边的小图标，setContentTitle()是通知的标题，setContentText()是通知的内容，一般标题的字体比内容要大一些。在api11以上也可以使用Notification.Builder来创建.

设置完参数后需要开启NotificationManager，获取它的实例通过

getSystemService(Context.NOTIFICATION_SERVICE)

Builder.build()返回的是一个Notification，Notifictionmanager的notify()方法要传入两个参数，第二个参数就是这个Notification类型。

这样一个通知就创建好了，点击按钮后拉开标题栏，会看到效果

public class MainActivity extends Activity {private static int id=1200;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);findViewById(R.id.button).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {                 NotificationCompat.Builder builder=new NotificationCompat.Builder(MainActivity.this )                 .setSmallIcon(R.drawable.ic_launcher)                 .setContentTitle("啊哦！你有一条新消息")                 .setContentText("你已经成功创建一条通知");                 NotificationManager mNotificationManager=(NotificationManager) getSystemService                 (Context.NOTIFICATION_SERVICE);                 mNotificationManager.notify(id, builder.build());                 }});}}

notify()的第一个参数是id,可以用来动态的改变通知的内容，比如我们设置一个count，用来记录点击的次数，每点击一次通知栏的count也会相应的改变

private static int count=0;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);findViewById(R.id.button).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {count++;                 NotificationCompat.Builder builder=new NotificationCompat.Builder(MainActivity.this )                 .setSmallIcon(R.drawable.ic_launcher)                 .setContentTitle("啊哦！你有"+count+"条新消息")                 .setContentText("你已经成功创建一条通知");                 NotificationManager mNotificationManager=(NotificationManager) getSystemService                 (Context.NOTIFICATION_SERVICE);                 // mId allows you to update the notification later on                 mNotificationManager.notify(id, builder.build());                 }});}

比如我点击按钮五次，通知会是这样的：

二）通知显示出来之后，我们需要给其设置点击事件，这里牵涉到PendingIntent的使用。

当从Notification开启一个Activity的时候，一般有两种情况，第一种情况是这个活动新开了一个活动栈，不占用应用的内存，按下返回键会直接返回到Home界面；第二种情况是给PendingIntent添加返回栈，在AndroidManifest文件里指明其父活动，当按下返回键的时候，带有返回栈的PendingIntent会复制原来活动正常的返回行为

1）开返回栈

先给目标活动注册，注意添加父活动，

      </intent-filter>        </activity>                <activity             android:name="com.example.notification.ResultActivity"            android:parentActivityName=".MainActivity">        </activity>

如果是android4.0.3之前的还要加上

<meta-data        android:name="android.support.PARENT_ACTIVITY"        android:value=".MainActivity"/>

然后在点击按钮里，这里在api16以下的要使用v4包里的TaskStackBuilder，我设置的最小sdk是14，所以使用的v4包。

                               Intent intent=new Intent(MainActivity.this,ResultActivity.class);android.support.v4.app.TaskStackBuilder stackBuilder=android.support.v4.app.TaskStackBuilder.create(MainActivity.this);stackBuilder.addParentStack(ResultActivity.class);//添加返回栈stackBuilder.addNextIntent(intent);//把intent添加到返回栈的栈顶PendingIntent pd=stackBuilder.getPendingIntent(0, PendingIntent.FLAG_CANCEL_CURRENT);                 NotificationCompat.Builder builder=new NotificationCompat.Builder(MainActivity.this )                 .setSmallIcon(R.drawable.ic_launcher)                 .setContentTitle("啊哦！你有"+count+"条新消息")                 .setContentText("你已经成功创建一条通知")                 .setContentIntent(pd);                 NotificationManager mNotificationManager=(NotificationManager) getSystemService                 (Context.NOTIFICATION_SERVICE);                 // mId allows you to update the notification later on                 mNotificationManager.notify(id, builder.build());

2）不加返回栈，直接在活动里写PendingIntent就可以

                 NotificationCompat.Builder builder=new NotificationCompat.Builder(MainActivity.this )                 .setSmallIcon(R.drawable.ic_launcher)                 .setContentTitle("啊哦！你有"+count+"条新消息")                 .setContentText("你已经成功创建一条通知");                             Intent intent=new Intent(MainActivity.this,ResultActivity.class);            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);PendingIntent pd=PendingIntent.getActivity(MainActivity.this, 0, intent,PendingIntent.FLAG_CANCEL_CURRENT);builder.setContentIntent(pd);                 NotificationManager mNotificationManager=(NotificationManager) getSystemService                 (Context.NOTIFICATION_SERVICE);                 // mId allows you to update the notification later on                 mNotificationManager.notify(id, builder.build());

三）给通知加上进度条

private NotificationManager mNotificationManager;private NotificationCompat.Builder builder;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);findViewById(R.id.button).setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {count++;mNotificationManager=(NotificationManager) getSystemService                (Context.NOTIFICATION_SERVICE);                 builder=new NotificationCompat.Builder(MainActivity.this )                 .setSmallIcon(R.drawable.ic_launcher)                 .setContentTitle("啊哦！你有"+count+"条新消息")                 .setContentText("你已经成功创建一条通知");                                                   new Thread(                    new Runnable() {                        @Override                        public void run() {                            int incr;                            // Do the "lengthy" operation 20 times                            for (incr = 0; incr <= 100; incr+=5) {                                    // Sets the progress indicator to a max value, the                                    // current completion percentage, and "determinate"                                    // state                                    builder.setProgress(100, incr, false);                                    // Displays the progress bar for the first time.                                    mNotificationManager.notify(0, builder.build());                                        // Sleeps the thread, simulating an operation                                        // that takes time                                        try {                                            // Sleep for 5 seconds                                            Thread.sleep(1000);                                        } catch (InterruptedException e) {                                        }                            }                            // When the loop is finished, updates the notification                           builder.setContentText("Download complete")                            // Removes the progress bar                                    .setProgress(0,0,false);                            mNotificationManager.notify(id, builder.build());                        }                    }                // Starts the thread by calling the run() method in its Runnable                ).start();}});}

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