A simple game framework SurfaceView use

 

SurfaceView use

 

android.view.SurfaceView is commonly used in game development framework , he inherited android.view.View, compared with View , surfaceView is starting in a new separate thread can redraw the screen while the View must be the main thread of the UI update screen . Therefore, development of the game , if the interface is required to use initiative to update SurfaceView ( eg racing , you need a separate thread to update the interface to prevent the main thread is blocked ) , a passive update ( board game ) can use the View frame ( call invalidate method to update ) .

 

described above rough SurfaceView and View. Here is a simple example to illustrate SurfaceView.

 

create a MySurfaceView.java

 

  

public class MySurfaceView extends SurfaceView implements Callback, Runnable { // 打开程序后，创建一个矩形，并让矩形随着时间而移动 
 
    int x = 0, y = 0, w = 40, h = 40, SrceenW, SrceenH; // 定义矩形的x,y坐标,宽高，以及手机的屏幕宽高 
    SurfaceHolder surfaceHolder; 
    Thread thread; // 定义一个线程，用来更新矩形所在的位置 
    int sleepTime = 100;// 让线程100毫秒更新一次界面 
    Paint paint; // 画笔 
    boolean flag = false;// 线程是否启动 
 
    public MySurfaceView(Context context, int SrceenW, int SrceenH) { 
        super(context); 
        surfaceHolder = getHolder(); 
        surfaceHolder.addCallback(this); 
        this.SrceenH = SrceenH; 
        this.SrceenW = SrceenW; 
        paint = new Paint(); 
        thread = new Thread(this); 
    } 
 
    /** 
     *  
     */ 
    public void draw(Canvas canvas) { 
        canvas.drawColor(Color.WHITE); 
        paint.setColor(Color.RED); 
        canvas.drawRect(x, y, x + w, y + h, paint); 
    } 
     
    /** 
     * 逻辑 
     */ 
    public void logic() { 
        if(x<=0){ 
            x=0; 
        } 
        if(y<=0){ 
            y=0; 
        } 
        if(x>=SrceenW-w){ 
            x=SrceenW-w; 
        } 
        if(y>=SrceenH-h){ 
            y=SrceenH-h; 
        } 
    } 
     
    @Override 
    public void surfaceCreated(SurfaceHolder holder) { // 启动线程绘制 
        // TODO Auto-generated method stub 
        flag = true; 
        if (!thread.isAlive()) { 
            thread.start(); 
        } 
    } 
 
    @Override 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, 
            int height) { 
        // TODO Auto-generated method stub 
 
    } 
 
    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { // 结束线程绘制 
        // TODO Auto-generated method stub 
        flag = false; 
        thread = null; 
    } 
 
    @Override 
    public void run() { // 绘制的更新过程 
        // TODO Auto-generated method stub 
        Canvas canvas = null; 
        while (flag) { 
            try { 
                canvas = surfaceHolder.lockCanvas(); //锁定画布开始绘制 
                synchronized (canvas) { 
                    logic(); 
                    draw(canvas); 
                } 
            } catch (Exception e) { 
                Log.e("mysurfaceview",e.getMessage()); 
            }finally{ 
                if(canvas!=null){ 
                    surfaceHolder.unlockCanvasAndPost(canvas);//解锁画布结束绘制 
                } 
            } 
            x++;  //x,y坐标改变 
            y++; 
            try { 
                Thread.sleep(sleepTime); //阻塞线程 
            } catch (Exception e) { 
                Log.e("mysurfaceview",e.getMessage()); 
            } 
        } 
    }

 

 

Activity Calling

 

  

public class SurfaceActivty extends Activity { 
 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        requestWindowFeature(Window.FEATURE_NO_TITLE); 
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
                WindowManager.LayoutParams.FLAG_FULLSCREEN); 
        // 获取屏幕宽高 
        Display display = getWindowManager().getDefaultDisplay(); 
        setContentView(new MySurfaceView(this,display.getWidth(),display.getHeight())); 
    } 
}