1.Handler默认情况下与主线程处于同一线程
public class MainActivity extends Activity {
private Button startButton = null;
private Button endButton = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startButton = (Button) findViewById(R.id.startButton);
endButton = (Button) findViewById(R.id.endButton);
startButton.setOnClickListener(new StartButtonListener());
endButton.setOnClickListener(new EndButtonListener());
/*
* if (savedInstanceState == null) {
* getSupportFragmentManager().beginTransaction() .add(R.id.container,
* new PlaceholderFragment()).commit(); }
*/
}
class StartButtonListener implements OnClickListener {
@Override
public void onClick(View v) {
System.out.println(Thread.currentThread().getId() + " Start");
handler.post(updateThread);
}
}
class EndButtonListener implements OnClickListener {
@Override
public void onClick(View v) {
System.out.println(Thread.currentThread().getId() + " End");
handler.removeCallbacks(updateThread);
}
}
Handler handler = new Handler();
Runnable updateThread = new Runnable() {
@Override
public void run() {
System.out
.println(Thread.currentThread().getId() + " UpdateThread");
handler.postDelayed(updateThread, 3000);
}
};
2.通过Handler实现进度条
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
tools:context="com.example.mars_1200_progressbarhandler.MainActivity"
tools:ignore="MergeRootFrame" > <TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="hello" /> <ProgressBar
android:id="@+id/bar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:visibility="gone" /> <Button
android:id="@+id/startButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="start" /> </LinearLayout>
public class MainActivity extends Activity {
ProgressBar bar = null;
Button startButton = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
System.out.println("主线程ID："+Thread.currentThread().getId());
bar = (ProgressBar) findViewById(R.id.bar);
startButton = (Button) findViewById(R.id.startButton);
startButton.setOnClickListener(new ButtonListener());
/*
* if (savedInstanceState == null) {
* getSupportFragmentManager().beginTransaction() .add(R.id.container,
* new PlaceholderFragment()).commit(); }
*/
}
class ButtonListener implements OnClickListener {
@Override
public void onClick(View v) {
bar.setVisibility(View.VISIBLE);
updateBarHandler.post(updateThread);
}
}
//使用匿名内部类
Handler updateBarHandler = new Handler() {
//可传递参数
@Override
public void handleMessage(Message msg) {
bar.setProgress(msg.arg1);
updateBarHandler.post(updateThread);
}
};
//线程类，该类使用匿名内部类的方式进行声明
Runnable updateThread = new Runnable() {
int i = 0;
@Override
public void run() {
System.out.println("Begin Thread");
System.out.println("Handler线程ID："+Thread.currentThread().getId());
i = i + 10;
//得到一个消息，Message类是有Android操作系统提供的
Message msg = updateBarHandler.obtainMessage();
//将msg对象的arg1参数的值设置为i，用arg1和arg2这两个
//成员变量传递值，优点是消耗性能小
msg.arg1 = i;
try {
Thread.sleep(1000);
} catch (Exception e) {
e.printStackTrace();
}
updateBarHandler.sendMessage(msg);
if (i >= 100) {
updateBarHandler.removeCallbacks(updateThread);
}
}
};
3.Handler通过post执行Runnable(还是与主线程处于同一线程)
public class MainActivity extends Activity {
private Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//handler线程和主线程在同一线程
handler.post(r);
/*Thread t=new Thread(r);
t.start();*/
System.out.println("activity-->" + Thread.currentThread().getId());
System.out.println("activityname-->" + Thread.currentThread().getId());
/*
* if (savedInstanceState == null) {
* getSupportFragmentManager().beginTransaction() .add(R.id.container,
* new PlaceholderFragment()).commit(); }
*/
}
Runnable r = new Runnable() {
@Override
public void run() {
System.out.println("handler-->" + Thread.currentThread().getId());
System.out.println("handlername-->"
+ Thread.currentThread().getName());
try {
Thread.sleep(10000);
} catch (Exception e) {
e.printStackTrace();
}
}
};
4.通过HandlerThread执行线程，并可通过Bundle传递参数
public class MainActivity02 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_activity02);
System.out.println(Thread.currentThread().getId());
//生成一个HandlerThread对象，实现了使用Looper来处理消息队列的功能，这个类由Android提供
HandlerThread handlerThread=new HandlerThread("handler_Thread");
handlerThread.start();
MyHandler myHandler=new MyHandler(handlerThread.getLooper());
Message msg=myHandler.obtainMessage();
msg.obj="abc";//通过obj存储数据
Bundle b=new Bundle();
b.putInt("age", 20);
b.putString("name", "Jhon");
msg.setData(b);//通过Bundle存储数据
msg.sendToTarget();//将msg发送到目标对象，所谓的目标对象就是生成该msg的Handler
/*if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}*/
}
class MyHandler extends Handler{
public MyHandler(){
}
public MyHandler(Looper looper){
super(looper);
}
@Override
public void handleMessage(Message msg){
System.out.println(msg.obj);
Bundle b=msg.getData();
System.out.println(b.getInt("age"));
System.out.println(b.getString("name"));
System.out.println("handleMessage:"+Thread.currentThread().getId());
}
}