Service给Activity传递参数更改UI

最新推荐文章于 2021-05-27 01:57:08 发布

原创最新推荐文章于 2021-05-27 01:57:08 发布 · 984 阅读

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#service #activiy #UI

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本文介绍了一个Android应用如何通过Service设置定时任务，并利用Handler在Activity中更新UI显示。通过AlarmManager实现每5秒重复触发Service，Service再向Activity发送消息更新文本视图。

handler在Activity中定义成public static形式，Service使用sendMessage()向Activity发送消息，Activity使用handleMessage()修改UI

package com.example.alarm_1;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {
	UserId userId = new UserId();
	private TextView textView1;
	public static Handler handler;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		textView1 = (TextView) findViewById(R.id.textView1);

		UserId.setId1("123");
		UserId.setId2("456");

		Intent intent = new Intent();
		intent.setClass(MainActivity.this, MyService.class);
		PendingIntent pendingIntent = PendingIntent.getService(this, 0, intent,
				0);
		AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
		Log.i("Alarm", "Alarm");
		// am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 5*1000,
		// pendingIntent); ///单次不重复

		am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),
				5 * 1000, pendingIntent);// ////TTTT 重复
		// /////////
		handler = new Handler() {
			@Override
			public void handleMessage(Message msg) {
				// TODO 自动生成的方法存根
				// super.handleMessage(msg);
				if (msg.what == 1) {
					String text = (String) msg.obj;
					textView1.setText(text);
				}
			}
		};// handler
	}// /onCreate

}// /MainActivity

package com.example.alarm_1;

import java.util.Date;

import android.app.Service;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Message;
import android.util.Log;
import android.widget.Toast;

/**
 * @author Administrator
 * 
 */

public class MyService extends Service {

	@Override
	public IBinder onBind(Intent intent) {
		// TODO 自动生成的方法存根

		return null;
	}

	@Override
	public void onCreate() {
		// TODO 自动生成的方法存根

	}

	@Override
	public void onStart(Intent intent, int startId) {

		String id11 = UserId.getId1();
		String id22 = UserId.getId2();
		Log.i("---------------onStart--------------",
				"-----------onStart---------------");
		Log.i("--------------------暂停----------------------", "暂停");
		 Toast.makeText(this, "暂停" + id11 + "," + id22, Toast.LENGTH_SHORT)
		 .show();
		Message msg = new Message();
		msg.what=1;
		//msg.obj="暂停";
		msg.obj=String.valueOf(System.currentTimeMillis());
	    MainActivity.handler.sendMessage(msg);
	}

	@Override
	public void onDestroy() {
		// TODO 自动生成的方法存根
		Log.i("---------------onDestroy--------------",
				"-----------onDestroy---------------");
	}

}//

package com.example.alarm_1;

public class UserId {
private  static   String id1;
private  static   String id2;

public static String getId1() {
	return id1;
}

public static void setId1(String id1) {
	UserId.id1 = id1;
}

public static String getId2() {
	return id2;
}

public static void setId2(String id2) {
	UserId.id2 = id2;
}


}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.alarm_1"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="16" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".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>

        <service
            android:name=".MyService"
            android:enabled="true" >
        </service>

    </application>

</manifest>

时间每5s变化一次，Toast每5s弹出一次