Android:Notification的生成与取消

　　MainActivity.java:

package com.example.notificationdemo;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.app.Notification;
import android.app.Notification.Builder;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;
import android.os.Build;

public class MainActivity extends Activity {
	Button btn_cancel;
	Button btn_generate;
	Notification notification;
	PendingIntent pintent;
	Intent intent;
	NotificationManager manager;// 后面要用

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btn_cancel = (Button) findViewById(R.id.btn_cancel);
		btn_generate = (Button) findViewById(R.id.btn_generate);
		btn_generate.setOnClickListener(new MyListener());
		btn_cancel.setOnClickListener(new MyListener());

	}

	public class MyListener implements OnClickListener {

		@Override
		public void onClick(View v) {
			switch (v.getId()) {
			case R.id.btn_generate:
				System.out.println("=========btn_generate=====");
				GenerateNotification();
				break;
			case R.id.btn_cancel:
				System.out.println("=========btn_cancel=====");
				CancelNotification();
				break;

			}
		}

	}

	private void GenerateNotification() {

		intent = new Intent(this, SecondActivity.class);
		pintent = PendingIntent.getActivity(this, 0, intent, 0);
		Builder builder = new Builder(this);
		builder.setSmallIcon(R.drawable.ic_launcher);
		builder.setTicker("这是手记状态栏提示");
		builder.setWhen(System.currentTimeMillis());
		builder.setContentTitle("woshi biaoti");
		builder.setContentText("标题内容我是");
		builder.setContentIntent(pintent);
		builder.setDefaults(Notification.DEFAULT_SOUND);
		builder.setDefaults(Notification.DEFAULT_LIGHTS);
		// builder.getNotification();//4.0以及以下版本用这个获取notification
		Notification notification = builder.build();// 4.1以及以上版本用这个
		Toast.makeText(this, "生成通知", 50).show();
		manager = (NotificationManager) this
				.getSystemService(NOTIFICATION_SERVICE);
		manager.notify(23, notification);// 发出通知
	}

	private void CancelNotification() {
		// if(manager.equals("")||manager==null){//不能这么判断，因为加入manager为空，那么null.equals("")肯定就会空指针异常
		if (manager == null) {
			Toast.makeText(this, "亲，暂时没有消息，所以无法取消", 50).show();
			return;
		} else {
			Toast.makeText(this, "取消", 50).show();
			manager.cancel(23);
		}

	}
}

　　

　　SecondActivity.java

package com.example.notificationdemo;

import android.app.Activity;
import android.os.Bundle;


public class SecondActivity extends Activity {

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

}

　 activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.notificationdemo.MainActivity"
    tools:ignore="MergeRootFrame" >

    <Button
        android:id="@+id/btn_cancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:text="取消通知" />

	<Button
	    android:id="@+id/btn_generate"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:layout_alignParentLeft="true"
	    android:layout_alignParentRight="true"
	    android:text="生成通知"
	    android:layout_below="@+id/btn_cancel" />
    
</RelativeLayout>

　　second_act.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.notificationdemo.MainActivity"
    tools:ignore="MergeRootFrame" >

	<TextView 
	    android:id="@+id/tv01"
	    android:text="我是第二页"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    />    
</RelativeLayout>

　　清單文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.notificationdemo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="19" />
    <uses-permission android:name="android.permission.FLASHLIGHT"/>
    <uses-permission android:name="android.permission.VIBRATE"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.notificationdemo.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.example.notificationdemo.SecondActivity"
            android:label="@string/app_name" >
        </activity>
    </application>

</manifest>

　　效果圖：

     遇到一个奇怪的事情：

如下：

package com.example.notificationdemo;

import android.app.Activity;
import android.app.Notification;
import android.app.Notification.Builder;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class SecondActivity extends Activity implements OnClickListener {
	Button btn;
	PendingIntent pintent;
	Intent intent;
	NotificationManager manager;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.second_act);
		System.out.println("second:" + Thread.currentThread().getName());
		Toast.makeText(this, "second:" + Thread.currentThread().getName(), 21)
				.show();
		btn = (Button) findViewById(R.id.sec_generate);
		Toast.makeText(this, "this is the second,begin to go back", 12).show();
		btn.setOnClickListener(this);
		System.out.println("第二页的，btn is onclicked");
	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.sec_generate:
			intent = new Intent(this,MainActivity.class);
			pintent = PendingIntent.getActivity(this, 0, intent, 0);//跳回第一页用
			Builder builder = new Builder(this);
			builder.setContentText("京东啊啊啊");
			builder.setContentTitle("GO BACK");
			builder.setSmallIcon(R.drawable.ic_launcher);//不设置SmallICon就没法跳转
//			Notification notification = builder.build();
			builder.setTicker("我是ticker");
			builder.setContentIntent(pintent);
			builder.setDefaults(Notification.DEFAULT_SOUND);
			builder.setDefaults(Notification.DEFAULT_LIGHTS);
			Notification notification = builder.build();//一定要放在setContentIntent()后
			manager = (NotificationManager) this.getSystemService(NOTIFICATION_SERVICE);
			Toast.makeText(this, "back to the mainactivity", 12).show();
			manager.notify(1, notification);
			System.out.println("=============se===========");
			break;
		}
	}

}

　　其中的builder.setSmallIcon(R.drawable.ic_launcher);如果注释掉，那么就不会生成相应的通知消息。暂时没找到原因，不知道为什么。