Android 游戲開發 View框架

按鍵盤的上下鍵矩形就會上下移動；

通過實例化Handler對象並重寫handkeMessage方法實現了一個消息接收器。然後再線程中通過sendMessage方法發送更新界面的消息，接收器收到更新界面的消息時便執行invalidate方法更新屏幕顯示。

  package com.yarin.android.TestOnView; 
 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.view.View; 
 
public class GameView extends View 
{ 
    int  miCount = 0; 
    int  y = 0; 
    public GameView(Context context) 
    { 
        super(context); 
    } 
      
    public void onDraw(Canvas canvas) 
    { 
        if (miCount < 100) 
        { 
            miCount++; 
        } 
        else 
        { 
            miCount = 0; 
        } 
        //繪圖  
        Paint mPaint = new Paint();   
        switch (miCount%4) 
        { 
        case 0: 
            mPaint.setColor(Color.BLUE);      
            break; 
        case 1: 
            mPaint.setColor(Color.GREEN);      
            break; 
        case 2: 
            mPaint.setColor(Color.RED);      
            break; 
        case 3: 
            mPaint.setColor(Color.YELLOW);      
            break; 
        default: 
            mPaint.setColor(Color.WHITE);      
            break; 
        } 
        //繪制矩形  
        canvas.drawRect((320-80)/2, y, (320-80)/2+80, y+40, mPaint); 
    } 
} 

package com.yarin.android.TestOnView;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;

public class GameView extends View
{
    int  miCount = 0;
    int  y = 0;
    public GameView(Context context)
    {
        super(context);
    }
    
    public void onDraw(Canvas canvas)
    {
        if (miCount < 100)
        {
            miCount++;
        }
        else
        {
            miCount = 0;
        }
        //繪圖
        Paint mPaint = new Paint(); 
        switch (miCount%4)
        {
        case 0:
            mPaint.setColor(Color.BLUE);    
            break;
        case 1:
            mPaint.setColor(Color.GREEN);    
            break;
        case 2:
            mPaint.setColor(Color.RED);    
            break;
        case 3:
            mPaint.setColor(Color.YELLOW);    
            break;
        default:
            mPaint.setColor(Color.WHITE);    
            break;
        }
        //繪制矩形
        canvas.drawRect((320-80)/2, y, (320-80)/2+80, y+40, mPaint);
    }

}上面是用來繪制界面的，我們還需要一個類來控制應用的操作

 package com.yarin.android.TestOnView; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.os.Handler; 
import android.os.Message; 
import android.view.KeyEvent; 
import android.view.MotionEvent; 
 
public class ControlView extends Activity 
{ 
    private static final int    REFRESH        = 0x000001; 
    
    
    private GameView            mGameView    = null; 
 
    
    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 
        super.onCreate(savedInstanceState); 
 
        
        this.mGameView = new GameView(this); 
 
        // 設置顯示為我們自定義的View(GameView)  
        setContentView(mGameView); 
 
        // 開啟線程  
        new Thread(new GameThread()).start(); 
    } 
 
    Handler    myHandler    = new Handler() 
    { 
        //接收到消息後處理  
        public void handleMessage(Message msg) 
        { 
            switch (msg.what) 
            { 
            case ControlView.REFRESH: 
                mGameView.invalidate(); 
                break; 
            } 
            super.handleMessage(msg); 
        }            
    }; 
 
    class GameThread implements Runnable 
    { 
        public void run() 
        { 
            while (!Thread.currentThread().isInterrupted()) 
            { 
                Message message = new Message(); 
                message.what = ControlView.REFRESH; 
                //發送消息  
                Activity01.this.myHandler.sendMessage(message); 
                try 
                { 
                    Thread.sleep(100); 
                } 
                catch (InterruptedException e) 
                { 
                    Thread.currentThread().interrupt(); 
                } 
            } 
        } 
    } 
    
    //當然這些事件也可以寫在GameView中  
    //觸筆事件  
    public boolean onTouchEvent(MotionEvent event) 
    { 
        return true; 
    } 
    
    //按鍵按下事件  
    public boolean onKeyDown(int keyCode, KeyEvent event) 
    { 
        return true; 
    } 
    
    //按鍵彈起事件  
    public boolean onKeyUp(int keyCode, KeyEvent event) 
    { 
        switch (keyCode) 
        { 
        //上方向鍵  
        case KeyEvent.KEYCODE_DPAD_UP: 
            mGameView.y-=3; 
            break; 
        //下方向鍵  
        case KeyEvent.KEYCODE_DPAD_DOWN: 
            mGameView.y+=3; 
            break; 
        } 
        return false; 
    } 
    
    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) 
    { 
        return true; 
    } 
} 

package com.yarin.android.TestOnView;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.MotionEvent;

public class ControlView extends Activity
{
    private static final int    REFRESH        = 0x000001;
  
  
    private GameView            mGameView    = null;

  
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

      
        this.mGameView = new GameView(this);

        // 設置顯示為我們自定義的View(GameView)
        setContentView(mGameView);

        // 開啟線程
        new Thread(new GameThread()).start();
    }

    Handler    myHandler    = new Handler()
    {
        //接收到消息後處理
        public void handleMessage(Message msg)
        {
            switch (msg.what)
            {
            case ControlView.REFRESH:
                mGameView.invalidate();
                break;
            }
            super.handleMessage(msg);
        }          
    };

    class GameThread implements Runnable
    {
        public void run()
        {
            while (!Thread.currentThread().isInterrupted())
            {
                Message message = new Message();
                message.what = ControlView.REFRESH;
                //發送消息
                Activity01.this.myHandler.sendMessage(message);
                try
                {
                    Thread.sleep(100);
                }
                catch (InterruptedException e)
                {
                    Thread.currentThread().interrupt();
                }
            }
        }
    }
  
    //當然這些事件也可以寫在GameView中
    //觸筆事件
    public boolean onTouchEvent(MotionEvent event)
    {
        return true;
    }
  
    //按鍵按下事件
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        return true;
    }
  
    //按鍵彈起事件
    public boolean onKeyUp(int keyCode, KeyEvent event)
    {
        switch (keyCode)
        {
        //上方向鍵
        case KeyEvent.KEYCODE_DPAD_UP:
            mGameView.y-=3;
            break;
        //下方向鍵
        case KeyEvent.KEYCODE_DPAD_DOWN:
            mGameView.y+=3;
            break;
        }
        return false;
    }
  
    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
    {
        return true;
    }
}