Android之Handler详解(三)
16lz
2021-01-23
c、将消息队列绑定到子线程上,主线程只管通过Handler往子线程的消息队列中投递消息即可。
package com.dxyh.test;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.HandlerThread;import android.os.Looper;import android.os.Message;import android.util.Log;public class MainActivity extends Activity {private final static String TAG = "HandlerTest";private final static int TASK_BEGIN= 1;private final static int TASK_1= 2;private final static int TASK_2= 3;private final static int TASK_END= 4;private MyHandler mHandler = null; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Log.i(TAG, "[M_TID:" + Thread.currentThread().getId() + "]" + "This is in main thread."); HandlerThread myLooperThread = new HandlerThread("my looper thread"); myLooperThread.start(); Looper looper = myLooperThread.getLooper(); mHandler = new MyHandler(looper); // 启动任务(消息只有标识,立即投递)mHandler.sendEmptyMessage(TASK_BEGIN);Log.i(TAG, "[S_ID:" + Thread.currentThread().getId() + "]" +"Send TASK_START to handler.");// 开始任务1(在mHandler的消息队列中获取一个Message对象,避免重复构造)Message msg1 = mHandler.obtainMessage(TASK_1);msg1.obj = "This is task1";mHandler.sendMessage(msg1);Log.i(TAG, "[S_ID:" + Thread.currentThread().getId() + "]" +"Send TASK_1 to handler.");// 开启任务2(和上面类似)Message msg2 = Message.obtain();msg2.arg1 = 10;msg2.arg2 = 20;msg2.what = TASK_2;mHandler.sendMessage(msg2);Log.i(TAG, "[S_ID:" + Thread.currentThread().getId() + "]" +"Send TASK_2 to handler.");// 结束任务(空消息体,延时2s投递)mHandler.sendEmptyMessageDelayed(TASK_END, 2000);Log.i(TAG, "[S_ID:" + Thread.currentThread().getId() + "]" +"Send TASK_END to handler."); } class MyHandler extends Handler { public MyHandler(Looper looper) { super(looper); } // 现在在每个case之后,你可以做任何耗时的操作了 @Override public void handleMessage(Message msg) { switch (msg.what) { case TASK_BEGIN: Log.i(TAG, "[H_TID:" + Thread.currentThread().getId() + "] Get TASK_BEGIN"); break; case TASK_1: Log.i(TAG, "[H_TID:" + Thread.currentThread().getId() + "] Get TASK_1"); break; case TASK_2: Log.i(TAG, "[H_TID:" + Thread.currentThread().getId() + "] Get TASK_2"); break; case TASK_END: Log.i(TAG, "[H_TID:" + Thread.currentThread().getId() + "] Get TASK_END"); finish(); break; } super.handleMessage(msg); } }}
运行结果:
更多相关文章
- Android应用程序键盘(Keyboard)消息处理机制分析(5)
- Android Sqlite 数据库多线程操作
- [Android] 图片JNI(C++\Java)高斯模糊 多线程
- Android应用程序中模拟发送键盘触摸消息
- SQLite多线程操作数据库
- Android 线程池使用
- android Thread 数据加载 ProgressDialog 请求超时处理 线程 Han