android 的Handler处理UI主线程外的耗时操作

package com.example.handlerdemowjj;

import android.app.Activity;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.util.Log;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends Activity {

// 另外的线程

private static final int MSG_SUCCESS = 0;// 获取成功的标识

private static final int MSG_FAILURE = 1;// 获取失败的标识

private Thread mThread;

TextView tv;

private Handler mHandler = new Handler(){

public void handleMessage(Message msg) {// 此方法在ui线程运行

switch (msg.what) {

case MSG_SUCCESS:

Log.v("logcat", "MSG_SUCCESS" + Thread.currentThread());

Log.v("logcat", "MSG_SUCCESS_ID:"

+ Thread.currentThread().getId() + ",name="

+ Thread.currentThread().getName());

Toast.makeText(getApplication(), "成功", Toast.LENGTH_LONG)

.show();

tv.setText("new.成功");

break;

case MSG_FAILURE:

Log.v("logcat", "MSG_FAILURE" + Thread.currentThread());

Toast.makeText(getApplication(), "失败", Toast.LENGTH_LONG)

.show();

break;

}

}

};

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

tv = (TextView) findViewById(R.id.tv);

Runnable runnable = new Runnable() {

@Override

public void run() {

//这是新的线程，可在这儿处理耗时的操作，更新不了UI界面的操作的

Log.v("logcat",

"new-Thread.currentThread()=" + Thread.currentThread());

Log.v("logcat", "new-Thread.currentThread().getId()="

+ Thread.currentThread().getId() + ",name="

+ Thread.currentThread().getName());

int i = 0;

if (i == 0) {

mHandler.obtainMessage(MSG_SUCCESS).sendToTarget();// 获取成功

} else {

mHandler.obtainMessage(MSG_FAILURE).sendToTarget();// 获取失败

}

}

};

if (mThread == null) {

Toast.makeText(getBaseContext(), "mThread == null",

Toast.LENGTH_LONG).show();

mThread = new Thread(runnable);

mThread.start();// 线程启动

} else {

Toast.makeText(getBaseContext(), "thread_started",

Toast.LENGTH_LONG).show();

}

}

}