Android 游戏开发 View框架

按键盘的上下键矩形就会上下移动；

通过实例化Handler对象并重写handkeMessage方法实现了一个消息接收器。然后再线程中通过sendMessage方法发送更新界面的消息，接收器收到更新界面的消息时便执行invalidate方法更新屏幕显示。

 

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;

        }

        //绘图

        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;

        }

        //绘制矩形

        canvas.drawRect((320-80)/2, y, (320-80)/2+80, y+40, mPaint);

    }

}

上面是用来绘制界面的，我们还需要一个类来控制应用的操作

 

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);



        // 设置显示为我们自定义的View(GameView)

        setContentView(mGameView);



        // 开启线程

        new Thread(new GameThread()).start();

    }



    Handler    myHandler    = new Handler()

    {

        //接收到消息后处理

        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;

                //发送消息

                Activity01.this.myHandler.sendMessage(message);

                try

                {

                    Thread.sleep(100);

                }

                catch (InterruptedException e)

                {

                    Thread.currentThread().interrupt();

                }

            }

        }

    }

   

    //当然这些事件也可以写在GameView中

    //触笔事件

    public boolean onTouchEvent(MotionEvent event)

    {

        return true;

    }

   

    //按键按下事件

    public boolean onKeyDown(int keyCode, KeyEvent event)

    {

        return true;

    }

   

    //按键弹起事件

    public boolean onKeyUp(int keyCode, KeyEvent event)

    {

        switch (keyCode)

        {

        //上方向键

        case KeyEvent.KEYCODE_DPAD_UP:

            mGameView.y-=3;

            break;

        //下方向键

        case KeyEvent.KEYCODE_DPAD_DOWN:

            mGameView.y+=3;

            break;

        }

        return false;

    }

   

    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)

    {

        return true;

    }

}