Android線程實例講解

   本文只是一個關於Android線程之間通信的例子，高手請自動略過。例子主要實現如下功能：進度條，音樂播放進度顯示，圖片的移動。

遊戲部分源碼:

LoadBar.java

package com.dance.mrljdx;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.DisplayMetrics;
import android.util.Log;
import android.widget.ProgressBar;
import android.widget.TextView;

public class LoadBar extends Activity {
    /** Called when the activity is first created. */
    TextView txview=null,txload=null;
    ProgressBar pBar=null;
    protected static final int stop=1;
    protected static final int start=2;
    int intCounter=1;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.loadbar);
        //DisplayMetrics 獲取屏幕信息
        DisplayMetrics dm=new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(dm);
        int screenwith=dm.widthPixels;
        int screenheigh=dm.heightPixels;
        txview=(TextView)findViewById(R.id.textwh);
        txload=(TextView)findViewById(R.id.loadtext);
        pBar=(ProgressBar)findViewById(R.id.pb);
        txview.setText("屏幕寬度:"+screenwith+"\n屏幕長度："+screenheigh);        //通過線程來改變ProgressBar的值

        new Thread(new Runnable() {
            public void run()
            {
                for (int i = 0; i <=pBar.getMax(); i++)
                {
                    try
                    {
                        Thread.sleep(100);
                        iintCounter=i+1;
                        if (i == pBar.getMax())
                        {
                            Message m = new Message();
                            m.what=LoadBar.stop; //what是一個整形值
                            LoadBar.this.myMessageHandler.sendMessage(m);
                            //將處理信息發送給myMessageHandler處理
                            break;
                        }
                        else
                        {
                            Message m = new Message();
                            m.what=LoadBar.start;
                            LoadBar.this.myMessageHandler.sendMessage(m);
                        }
                    }
                    catch (Exception e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
}
//重構Handler方法
Handler myMessageHandler = new Handler()
{
  // @Override
      public void handleMessage(Message msg)
      {
          switch (msg.what)
          {
          //ProgressBar已經是對大值
          case LoadBar.stop:
              //設置Intent，跳轉到其他Activity
              Intent mIntent=new Intent();
              mIntent.setClass(LoadBar.this, Menu.class);
              startActivity(mIntent);
              Log.d("Lua", "Main==class");
              Thread.currentThread().interrupt();
              finish();
              break;
          case LoadBar.start:
              if (!Thread.currentThread().isInterrupted())
              {
                  // 改變ProgressBar的當前值
                  pBar.setProgress(intCounter);
                  // 設置標題欄中前景的一個進度條進度值
                  Log.d("Lua", "LoadBar線程");
                  txload.setText("  加載中 "+intCounter+"%");
              }
              break;
          }
          super.handleMessage(msg);
     }
    };
}

Game.java

 

package com.dance.mrljdx;

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.SeekBar;
public class Game extends Activity {
    MediaPlayer mediaPlayer;
    ImageButton imgbt1,imgbt2,imgbt3,openbt;
    OnClickListener listener1=null;
    OnClickListener listener2=null;
    OnClickListener listener3=null;
    OnClickListener listener4=null;
    OnClickListener openlistener=null;
    SeekBar sBar;
    Animation myAnimation;
    ImageView img1;
    private static final int start=1;
    private static final int end=2;
//  int position=mediaPlayer.getCurrentPosition();
    int pb,i;
    double current;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.game);
        setListener();
        imgbt1=(ImageButton)findViewById(R.id.btleft);
        imgbt1.setOnClickListener(listener1);
        imgbt2=(ImageButton)findViewById(R.id.btright);
        imgbt2.setOnClickListener(listener2);
        imgbt3=(ImageButton)findViewById(R.id.btup);
        imgbt3.setOnClickListener(listener3);
//        openbt=(ImageButton)findViewById(R.id.btopen);
        sBar=(SeekBar)findViewById(R.id.seek);
        pb=sBar.getProgress();
        myAnimation= AnimationUtils.loadAnimation(this,R.anim.img);
        img1=(ImageView) this.findViewById(R.id.img1);

    }
    void setListener(){
        listener1=new OnClickListener() {
            public void onClick(View v) {
                initSound();
            }
        };
        listener2=new OnClickListener() {
            public void onClick(View v) {
                stopMusic();
            }
        };
        listener3=new OnClickListener() {
            public void onClick(View v) {
                img1.setVisibility(View.INVISIBLE);
            }
        };
        openlistener=new OnClickListener() {
            public void onClick(View v) {
                // TODO Auto-generated method stub
                choosMusic();
            }
        };
    }
        //遊戲音效
    void initSound(){
        mediaPlayer=MediaPlayer.create(this,R.raw.gf);
        if(!mediaPlayer.isPlaying()){
            mediaPlayer.start();//播放聲音
            img1.setVisibility(View.VISIBLE);
            img1.startAnimation(myAnimation);
        }
        new Thread(new Runnable() {

            public void run() {
                // TODO Auto-generated method stub

                while(current<1){
                    Message m=new Message();
                    if(mediaPlayer.isPlaying()){
                        current=(double)mediaPlayer.getCurrentPosition()/mediaPlayer.getDuration();
//                      Log.d("Lua", "==當前音樂是否播放="+mediaPlayer.isPlaying());
                        m.what=Game.start;
                        Game.this.musicHandler.sendMessage(m);
                    }else {
                        Log.d("Lua", "當前音樂是否播放="+mediaPlayer.isPlaying());
                        m.what=Game.end;
                        Game.this.musicHandler.sendMessage(m);
                        break;
                    }
                }
            }
        }).start();
    }
    //停止播放音樂
    void stopMusic(){
        if(mediaPlayer.isPlaying()){
            mediaPlayer.stop();//暫停聲音
        }
        this.finish();
    }
    //選擇播放的音樂
    void choosMusic(){

    }
    Handler musicHandler = new Handler(){
        public void handleMessage(Message msg) {
            switch(msg.what)
            {
            case Game.start:
                if (!Thread.currentThread().isInterrupted())
                {
                    int i=new Double(current*100).intValue();
                    Log.d("Lua", "==當期音樂播放位置="+i);
                    // 改變ProgressBar的當前值
                    sBar.setProgress(i+1);
                }
              break;
            case Game.end:
                Log.d("Lua", "當前音樂是否播放="+mediaPlayer.isPlaying());
                Thread.currentThread().interrupt();
                break;
            }

        }
    };
}

遊戲截圖：