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package com.ideasandroid.demo; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.view.MotionEvent; import android.view.SurfaceHolder; import android.view.SurfaceView; public class MTView extends SurfaceView implements SurfaceHolder.Callback {
  	private static final int MAX_TOUCHPOINTS = 10; 	private static final String START_TEXT = "请随便触摸屏幕进行测试"; 	private Paint textPaint = new Paint(); 	private Paint touchPaints[] = new Paint[MAX_TOUCHPOINTS]; 	private int colors[] = new int[MAX_TOUCHPOINTS]; 	private int width, height; 	private float scale = 1.0f; 	public MTView(Context context) {
  		super(context); 		SurfaceHolder holder = getHolder(); 		holder.addCallback(this); 		setFocusable(true); // 确保我们的View能获得输入焦点 		setFocusableInTouchMode(true); // 确保能接收到触屏事件 		init(); 	} 	private void init() {
  		// 初始化10个不同颜色的画笔 		textPaint.setColor(Color.WHITE); 		colors[0] = Color.BLUE; 		colors[1] = Color.RED; 		colors[2] = Color.GREEN; 		colors[3] = Color.YELLOW; 		colors[4] = Color.CYAN; 		colors[5] = Color.MAGENTA; 		colors[6] = Color.DKGRAY; 		colors[7] = Color.WHITE; 		colors[8] = Color.LTGRAY; 		colors[9] = Color.GRAY; 		for (int i = 0; i < MAX_TOUCHPOINTS; i++) {
  			touchPaints[i] = new Paint(); 			touchPaints[i].setColor(colors[i]); 		} 	} 	/* 	 * 处理触屏事件 	 */ 	@Override 	public boolean onTouchEvent(MotionEvent event) {
  		// 获得屏幕触点数量 		int pointerCount = event.getPointerCount(); 		if (pointerCount > MAX_TOUCHPOINTS) {
  			pointerCount = MAX_TOUCHPOINTS; 		} 		// 锁定Canvas,开始进行相应的界面处理 		Canvas c = getHolder().lockCanvas(); 		if (c != null) {
  			c.drawColor(Color.BLACK); 			if (event.getAction() == MotionEvent.ACTION_UP) {
  				// 当手离开屏幕时，清屏 			} else {
  				// 先在屏幕上画一个十字，然后画一个圆 				for (int i = 0; i < pointerCount; i++) {
  					// 获取一个触点的坐标，然后开始绘制 					int id = event.getPointerId(i); 					int x = (int) event.getX(i); 					int y = (int) event.getY(i); 					drawCrosshairsAndText(x, y, touchPaints[id], i, id, c); 				} 				for (int i = 0; i < pointerCount; i++) {
  					int id = event.getPointerId(i); 					int x = (int) event.getX(i); 					int y = (int) event.getY(i); 					drawCircle(x, y, touchPaints[id], c); 				} 			} 			// 画完后，unlock 			getHolder().unlockCanvasAndPost(c); 		} 		return true; 	} 	/** 	 * 画十字及坐标信息 	 * 	 * @param x 	 * @param y 	 * @param paint 	 * @param ptr 	 * @param id 	 * @param c 	 */ 	private void drawCrosshairsAndText(int x, int y, Paint paint, int ptr, 			int id, Canvas c) {
  		c.drawLine(0, y, width, y, paint); 		c.drawLine(x, 0, x, height, paint); 		int textY = (int) ((15 + 20 * ptr) * scale); 		c.drawText("x" + ptr + "=" + x, 10 * scale, textY, textPaint); 		c.drawText("y" + ptr + "=" + y, 70 * scale, textY, textPaint); 		c.drawText("id" + ptr + "=" + id, width - 55 * scale, textY, textPaint); 	} 	/** 	 * 画圆 	 * 	 * @param x 	 * @param y 	 * @param paint 	 * @param c 	 */ 	private void drawCircle(int x, int y, Paint paint, Canvas c) {
  		c.drawCircle(x, y, 40 * scale, paint); 	} 	/* 	 * 进入程序时背景画成黑色，然后把“START_TEXT”写到屏幕 	 */ 	public void surfaceChanged(SurfaceHolder holder, int format, int width, 			int height) {
  		this.width = width; 		this.height = height; 		if (width > height) {
  			this.scale = width / 480f; 		} else {
  			this.scale = height / 480f; 		} 		textPaint.setTextSize(14 * scale); 		Canvas c = getHolder().lockCanvas(); 		if (c != null) {
  			// 背景黑色 			c.drawColor(Color.BLACK); 			float tWidth = textPaint.measureText(START_TEXT); 			c.drawText(START_TEXT, width / 2 - tWidth / 2, height / 2, 					textPaint); 			getHolder().unlockCanvasAndPost(c); 		} 	} 	public void surfaceCreated(SurfaceHolder holder) {
  	} 	public void surfaceDestroyed(SurfaceHolder holder) {
  	} }

package com.ideasandroid.demo; import android.app.Activity; import android.os.Bundle; import android.view.Window; import android.view.WindowManager; public class MultitouchVisible extends Activity {
      @Override     public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);         //隐藏标题栏         requestWindowFeature(Window.FEATURE_NO_TITLE);         //设置成全屏         getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,         		WindowManager.LayoutParams.FLAG_FULLSCREEN);         //设置为上面的MTView         setContentView(new MTView(this));     } }

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