Looper、Handler进一步学习

package com.test.looper;

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 LooperThread  looperThread;//自己实现的带有Looper的类
private HandlerThread handerThread;//使用sdk方便类，带有Looper
private Handler handler;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        looperThread = new LooperThread();
        looperThread.start();
looperThread.getHandler().sendEmptyMessage(1);
looperThread.exit();

handerThread = new HandlerThread("abc");
handerThread.start();

//Handler在构造时会关联一个Looper，如果空就会使用Looper.myLooper();详见源码
handler = new Handler(handerThread.getLooper()){
@Override
public void handleMessage(Message msg) {
Log.d("CYQ", "--->" + msg);
}
};
handler.sendEmptyMessage(100);
    }


    class LooperThread extends Thread {
        private Handler mHandler;
        private final Object mSync = new Object();

        public void run() {
            Looper.prepare();
            synchronized (mSync) {
                mHandler = new Handler(){
                @Override
                public void handleMessage(Message msg) {
                Log.d("CYQ", "--->" + msg);
                }
                };
                mSync.notifyAll();
            }
            Looper.loop();
        }

        public Handler getHandler() {
            synchronized (mSync) {
                if (mHandler == null) {
                    try {
                        mSync.wait();
                    } catch (InterruptedException e) {
                    }
                }
                return mHandler;
            }
        }
        public void exit() {
            getHandler().post(new Runnable(){
                public void run() {
                    Looper.myLooper().quit();
                }});
        }
    }
}

发现sdk中有方便类，可以有另外一种实现方法

HandlerThread的Looper对象可以用于创建一个Handler