目录

2、 使用SurfaceView画2D图

范例一

设计GameLoop(把小线程移出来)

范例二

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2、 使用SurfaceView画2D图

范例一

• 以SurfaceView绘出Bitmap图像
• 设计SpriteView类别来实作SurfaceHolder.Callback接口
• 首先来看个简单的程序，显示出一个Bitmap图像。这个图像就构成Sprite动画的基本图形。这个图像如下：
  

   

// SpriteView.java
// ………
public class SpriteView implements SurfaceHolder.Callback{private SpriteThread sThread;private Paint paint;private Bitmap bm;public SpriteView(Bitmap bmp) { bm = bmp; }@Override public void surfaceCreated(SurfaceHolder holder) {sThread = new SpriteThread(holder, this);sThread.start();}@Override public void surfaceDestroyed(SurfaceHolder holder) {}@Overridepublic void surfaceChanged(SurfaceHolder holder, int format,int width, int height) {}protected void onDraw(Canvas canvas) {paint= new Paint();canvas.drawColor(Color.WHITE);canvas.drawBitmap(bm, 10, 10, paint);
}public class SpriteThread extends Thread{private SpriteView mView;private SurfaceHolder mHolder;private Canvas c;SpriteThread(SurfaceHolder h, SpriteView v){mHolder = h mView = v;}public void run(){try{c = mHolder.lockCanvas(null);synchronized (mHolder){mView.onDraw(c);}}finally{if(c!=null)mHolder.unlockCanvasAndPost(c);}}
}

设计GameLoop(把小线程移出来)

// SpriteView.java
// ……..
public class SpriteView implements SurfaceHolder.Callback{private SpriteThread sThread;private Paint paint;private Bitmap bm;public SpriteView(Bitmap bmp) { bm = bmp; }@Overridepublic void surfaceCreated(SurfaceHolder holder) {sThread = new SpriteThread(holder, this);sThread.start();}@Overridepublic void surfaceDestroyed(SurfaceHolder holder){ }@Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height) { }protected void onDraw(Canvas canvas) {paint= new Paint();canvas.drawColor(Color.WHITE);canvas.drawBitmap(bm, 10, 10, paint);}
}// SpriteThread.java
//……….
public class SpriteThread extends Thread {private SpriteView mView;private SurfaceHolder mHolder;private Canvas c;SpriteThread(SurfaceHolder h, SpriteView v){mHolder = h; mView = v;}public void run(){try{c = mHolder.lockCanvas(null);synchronized (mHolder){ mView.onDraw(c); }}finally{if(c!=null){ mHolder.unlockCanvasAndPost(c); }}}
}

// myActivity.java
// ……..
public class myActivity extends Activity implements OnClickListener {private SurfaceView sv = null;private Button ibtn;private Bitmap bm;private SpriteView spView;@Override protected void onCreate(Bundle icicle) {super.onCreate(icicle);LinearLayout layout = new LinearLayout(this);layout.setOrientation(LinearLayout.VERTICAL);sv = new SurfaceView(this);bm = BitmapFactory.decodeResource(getResources(), R.drawable.walk_elaine);spView = new SpriteView(bm);sv.getHolder().addCallback(spView);LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(200, 200);param.topMargin = 10; param.leftMargin = 10;layout.addView(sv, param);//----------------------------------------------ibtn = new Button(this); ibtn.setOnClickListener(this);ibtn.setText("Exit");ibtn.setBackgroundResource(R.drawable.gray);LinearLayout.LayoutParams param1 = new LinearLayout.LayoutParams(200, 65);param1.topMargin = 10; param1.leftMargin = 10;layout.addView(ibtn, param1);setContentView(layout);}public void onClick(View v) { finish(); }
}

范例二

• 让图像在SurfaceView里旋转
  

         

• 在MySurfaceView里定义一个DrawThread类，它诞生一个单独的线程来执行画图的任务。
• 当主线程侦测到绘图画面(Surface)被开启时，就会诞生DrawThread对象，启动新线程去画图。
• 一直到主要线程侦测到绘图画面被关闭时，就停此正在绘图的线程。
  

class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback {private SurfaceHolder mHolder;private DrawThread mThread;MySurfaceView(Context context) {super(context);getHolder().addCallback(this);}public void surfaceCreated(SurfaceHolder holder) {mHolder = holder;mThread = new DrawThread();mThread.start(); }public void surfaceDestroyed(SurfaceHolder holder) {mThread.finish();mThread = null;}public void surfaceChanged(SurfaceHolder holder, int format,int w, int h) { }class DrawThread extends Thread {int degree = 36;boolean mFinished = false;DrawThread() { super(); }@Override public void run() {Bitmap bmp = BitmapFactory.decodeResource(getResources(),R.drawable.x_xxx);Matrix matrix;degree = 0;while(!mFinished){Paint paint = new Paint(); paint.setColor(Color.CYAN);Canvas cavans = mHolder.lockCanvas();cavans.drawCircle(80, 80, 45, paint);//------ rotate -----------------------------matrix = new Matrix(); matrix.postScale(1.5f, 1.5f);matrix.postRotate(degree);Bitmap newBmp= Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(),bmp.getHeight(), matrix, true);cavans.drawBitmap(newBmp, 50, 50, paint);mHolder.unlockCanvasAndPost(cavans);degree += 15;try { Thread.sleep(100);} catch (Exception e) {}}}void finish(){ mFinished = true; }}
}

 

// ac01.java-
//……..
public class ac01 extends Activity {@Override protected void onCreate(Bundle icicle) {super.onCreate(icicle);MySurfaceView mv = new MySurfaceView(this);LinearLayout layout = new LinearLayout(this);layout.setOrientation(LinearLayout.VERTICAL);LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(200, 150);param.topMargin = 5;layout.addView(mv, param);setContentView(layout);}
}