看mars的视频，学的一些代码：
package com.example.handletest;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
* 简单的例子：
* 包含：
* 1.一个handler
* 2.一个线程
* 两个button通过handler控制：线程进入handler的线程队列
* 线程进入handler队列后会自动调用run方法运行
* @author hongyehwy
*/
public class MainActivity extends Activity {
private static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
private Button starButton;
private Button endButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
starButton = (Button)findViewById(R.id.button_satrt);
starButton.setOnClickListener(new StartListener());
endButton = (Button)findViewById(R.id.button_end);
endButton.setOnClickListener(new EndListener());
}
private Handler myHandler = new Handler();
class StartListener implements OnClickListener{
@Override
public void onClick(View v) {
myHandler.post(myThread);
}
}
class EndListener implements OnClickListener{
@Override
public void onClick(View v) {
myHandler.removeCallbacks(myThread);
System.out.println("stop");
}
}
//一个线程变量
Runnable myThread = new Runnable(){
@Override
public void run() {
System.out.println("thread-"+ Thread.currentThread().getName()+" run @ "+sdf.format(new Date()));
myHandler.postDelayed(myThread, 3000);
}
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
demo2：
package com.example.handleandprogressbar;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
/**
*
* @author hongyehwy
* 部件
* 1.两个button，分别控制进度条的前进、停止前进
* 2.进度条
* 执行过程：
* 1.button 通过 handler控制线程的启动，线程启动后增加progressbar的进度,并将增加后的值传递到数据队列
* 2.handler重写handleMessage方法，从msg中获取当前progressbar的大小，调用progressbar的方法更新progressbar
* 3.当progressbar的大小 > 100的时候，从线程队列中删除线程
*
*/
public class MainActivity extends Activity {
private ProgressBar pb;
private Button start;
private Button end;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pb = (ProgressBar)findViewById(R.id.progressBar);
start = (Button)findViewById(R.id.button_start);
start.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
pb.setVisibility(View.VISIBLE);
progressBarHandler.post(updateThread);
}
});
end = (Button)findViewById(R.id.button_end);
end.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
progressBarHandler.removeCallbacks(updateThread);
}
});
}
//处理progressBar的Handler
private Handler progressBarHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
pb.setProgress(msg.arg1);
progressBarHandler.post(updateThread);
};
};
//处理progressBar的线程
private Runnable updateThread = new Runnable() {
int i = 0;
@Override
public void run() {
System.out.println("start updateThread ");
if( i < 100){
i = i + 10;
Message msg = progressBarHandler.obtainMessage();
msg.arg1 = i;
try{
Thread.sleep(1000);
}catch (Exception e) {
}
progressBarHandler.sendMessage(msg);
}else{
progressBarHandler.removeCallbacks(this);
}
}
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
前面两个demo中，都是在主线程中操作handle对象，并不是实际意义上的异步线程操作。
下面的demo通过HandlerThread获取一个非主线程looper，然后在这个looper中处理这些异步操作。
demo3
package com.example.handletest;
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.view.Menu;
/**
* 简单的例子：
* 包含：
* 1.一个HandlerThread
* 2.一个继承自Handler的类，添加带looper参数的构造函数,重载handlerMessage方法
* 执行过程：
* 1.通过HandlerThread获得一个非主线程的looper对象，并将这个looper对象分配给Handler对象。
* 2.获取Handler的msg，填充msg对象（发送异步线程消息消息），并在Handler对象的handleMessage方法中处理这个消息。
*
* @author hongyehwy
*/
public class MainActivity2 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
System.out.println("activity thread id-->"+Thread.currentThread().getId());
System.out.println("activity thread name-->"+Thread.currentThread().getName());
HandlerThread hThread = new HandlerThread("Handler Thread");
hThread.start();
MyHandler myHandler = new MyHandler(hThread.getLooper());
Message msg = myHandler.obtainMessage();
Bundle bundle = new Bundle();
bundle.putString("name", "kate");
bundle.putString("age", "18");
msg.setData(bundle);
msg.sendToTarget();
}
class MyHandler extends Handler{
public MyHandler() {}
public MyHandler(Looper looper) {
super(looper);
}
@Override
public void handleMessage(Message msg) {
System.out.println("MyHandler thread id-->"+Thread.currentThread().getId());
System.out.println("MyHandler thread name-->"+Thread.currentThread().getName());
Bundle bundle = msg.getData();
System.out.println("name = "+bundle.getString("name")+" ; age = "+bundle.getString("age"));
};
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}