在开发之中子线程都是完成一些比较浪费时间的操作，这些操作不应涉及显示的操作，而只是涉及到数据的操作。
在main.xml中：
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_horizontal"
android:background="#000000"
android:orientation="vertical">
<TextView
android:id="@+id/msg"
android:gravity="center_horizontal"
android:layout_marginTop="8dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:textColor="#ffffff"
android:text="等待子线程发送信息"/>
<Button
android:id="@+id/but"
android:layout_marginTop="18dp"
android:layout_width="80dp"
android:layout_height="40dp"
android:background="#3399ff"
android:textColor="#ffffff"
android:text="进行交互"/>
</LinearLayout>
在MyThreadDemo.java中：
package com.li.threadproject;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.support.v4.app.NavUtils;
public class MyThreadDemo extends Activity {
public static final int SETMAIN = 1; //设置一个what的标记
public static final int SETCHILD = 2; //设置一个what的标记
private Handler mainHandler,childHandler;
private TextView msg = null;
private Button but = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.main);
this.msg = (TextView)super.findViewById(R.id.msg);
this.but = (Button)super.findViewById(R.id.but);
this.mainHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch(msg.what){
case SETMAIN:
MyThreadDemo.this.msg.setText("主线程接收数据：" +
msg.obj.toString());
}
}
};
new Thread(new ChildThread(),"Child Thread").start();
this.but.setOnClickListener(new OnClickListenerImpl());
}
private class OnClickListenerImpl implements OnClickListener{
public void onClick(View v) { //将信息发送到子线程中
if(MyThreadDemo.this.childHandler !=null){
Message childMsg = MyThreadDemo.this.childHandler
.obtainMessage(); //创建消息
childMsg.obj = MyThreadDemo.this.mainHandler.getLooper()
.getThread().getName() + "Hello 李叶文";
childMsg.what = SETCHILD;
MyThreadDemo.this.childHandler.sendMessage(childMsg);
}
}
}
class ChildThread implements Runnable{ //子线程
public void run() {
Looper.prepare();
MyThreadDemo.this.childHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
switch(msg.what){
case SETCHILD: //子线程接收主线程发送来的消息
System.out.println("### Main Child Message:" + msg.obj);
Message toMain = MyThreadDemo.this.mainHandler.obtainMessage();
toMain.obj = "这是子线程发送给主线程的信息" + super.getLooper()
.getThread().getName();
toMain.what = SETMAIN;
MyThreadDemo.this.mainHandler.sendMessage(toMain);
break;
}
}
};
Looper.loop(); //创建消息队列
}
}
@Override
protected void onDestroy() { //复写onDestroy方法以收尾
super.onDestroy();
MyThreadDemo.this.childHandler.getLooper().quit(); //结束子线程的操作队列
}
}