线程执行

Question

我有两个线程t1和t2。每个都有代码

getWindow().getDecorView().setBackgroundColor(Color.GREEN);

问题是该行不适用于Thread t2和主线程。

以下是代码：

package arj.developer.jaadu;

import android.app.Activity;
import android.graphics.Color;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends Activity {
    MediaPlayer mp1,mp2;
    View v;
    Thread t1 = new Thread(){
        public void run(){
            getWindow().getDecorView().setBackgroundColor(Color.CYAN);          
            mp1=MediaPlayer.create(MainActivity.this,R.raw.jaad);
            mp1.start();
        }
    };
    Thread t2= new Thread(){
        public void run(){
            getWindow().getDecorView().setBackgroundColor(Color.MAGENTA);
            mp2=MediaPlayer.create(MainActivity.this,R.raw.jaad);
            mp1.stop();
            mp2.start();
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().getDecorView().setBackgroundColor(Color.GREEN);
        try {
            t1.sleep(10000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        t1.start();
        try {
            t2.sleep(30000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        t2.start();
    }
}

Answer 1

sleep()导致CURRENT线程进入休眠状态，因此t1.sleep(10000)和t2.sleep(10000)都导致主线程进入休眠状态！ 将睡眠方法移至t1＆amp; t2的run()方法，您可能也应该在主线程中运行getWindow().getDecorView().setBackgroundColor(_color_);。

package arj.developer.jaadu;

import android.app.Activity;
import android.graphics.Color;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends Activity {
    MediaPlayer mp1,mp2;
    View v;
    Thread t1 = new Thread(){
        public void run(){
            try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            runOnUiThread(new Runnable() {

            @Override
            public void run() {
                                getWindow().getDecorView().setBackgroundColor(Color.CYAN);   
            }
        });       
            mp1=MediaPlayer.create(MainActivity.this,R.raw.jaad);
            mp1.start();
            try {
                Thread.sleep(30000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            runOnUiThread(new Runnable() {

            @Override
            public void run() {
                                getWindow().getDecorView().setBackgroundColor(Color.MAGENTA);
            }
        });   
            mp2=MediaPlayer.create(MainActivity.this,R.raw.jaad);
            mp1.stop();
            mp2.start();
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().getDecorView().setBackgroundColor(Color.GREEN);
        t1.start();
    }
}