java - 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。

这是代码：

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()导致当前线程休眠，因此您t1.sleep(10000)和t2.sleep(10000)两者都导致主线程休眠！将 sleep 方法移至 t1 & t2 的run()方法，您可能也应该getWindow().getDecorView().setBackgroundColor(_color_);在主线程中运行。

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();
    }
}