Android-------自定义圆形图片实现多点触控

详情见链接：http://www.cnblogs.com/gaoliangjie/p/5569671.html

public class MyView extends ImageView {    private Paint p;    static final int NONE = 0;    static final int DRAG = 1;     //拖动中    static final int ZOOM = 2;     //缩放中    static final int BIGGER = 3;   //放大ing    static final int SMALLER = 4;  //缩小ing    private int mode = NONE;       //当前的事件    private float beforeLenght;   //两触点距离    private float afterLenght;    //两触点距离    private float scale = 0.04f;  //缩放的比例 X Y方向都是这个值 越大缩放的越快    private int screenW;    private int screenH;    /*处理拖动 变量 */    private int start_x;    private int start_y;    private int stop_x;    private int stop_y;    private TranslateAnimation trans; //处理超出边界的动画    public MyView(Context context) {        super(context);    }    public MyView(Context context, AttributeSet attrs) {        super(context, attrs);        p = new Paint();    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        p.setColor(Color.YELLOW);        canvas.drawCircle(100, 100, 50, p);    }    private Bitmap getCircleBitmap(Bitmap bitmap, int pixels) {        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);        Canvas canvas = new Canvas(output);        final int color = 0xff424242;        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());        p.setAntiAlias(true);        int x = bitmap.getWidth();        canvas.drawCircle(x / 2, x / 2, x / 2, p);        p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));        canvas.drawBitmap(bitmap, rect, rect, p);        return output;    }    /**     * 该构造函数在动态创建时，指定图片的初始高宽     * @param context     * @param w     * @param h     */    public MyView(Context context,int w,int h) {        super(context);        this.setPadding(0, 0, 0, 0);        screenW = w;        screenH = h;    }    /**     * 就算两点间的距离     */    private float spacing(MotionEvent event) {        float x = event.getX(0) - event.getX(1);        float y = event.getY(0) - event.getY(1);        double d=x*x+y*y;        return (float) Math.sqrt(d);    }    /**     * 处理触碰..     */    @Override    public boolean onTouchEvent(MotionEvent event)    {        switch (event.getAction() & MotionEvent.ACTION_MASK) {            case MotionEvent.ACTION_DOWN:                mode = DRAG;                stop_x = (int) event.getRawX();                stop_y = (int) event.getRawY();                start_x = (int) event.getX();                start_y = stop_y - this.getTop();                String s = String.valueOf(start_x);                Toast.makeText(getContext(),"当前点击的x的值："+s,Toast.LENGTH_SHORT).show();                if (event.getPointerCount() == 2)                    beforeLenght = spacing(event);                break;            case MotionEvent.ACTION_POINTER_DOWN:                if (spacing(event) > 10f) {                    mode = ZOOM;                    beforeLenght = spacing(event);                }                break;            case MotionEvent.ACTION_UP:           /*判断是否超出范围     并处理*/                int disX = 0;                int disY = 0;                if(getHeight()<=screenH || this.getTop()<0)                {                    if(this.getTop()<0 )                    {                        int dis = getTop();                        this.layout(this.getLeft(), 0, this.getRight(), 0 + this.getHeight());                        disY = dis - getTop();                    }                    else if(this.getBottom()>screenH)                    {                        disY = getHeight()- screenH+getTop();                        this.layout(this.getLeft(), screenH-getHeight(), this.getRight(), screenH);                    }                }                if(getWidth()<=screenW)                {                    if(this.getLeft()<0)                    {                        disX = getLeft();                        this.layout(0, this.getTop(), 0+getWidth(), this.getBottom());                    }                    else if(this.getRight()>screenW)                    {                        disX = getWidth()-screenW+getLeft();                        this.layout(screenW-getWidth(), this.getTop(), screenW, this.getBottom());                    }                }                if(disX!=0 || disY!=0)                {                    trans = new TranslateAnimation(disX, 0, disY, 0);                    trans.setDuration(500);                    this.startAnimation(trans);                }                mode = NONE;                break;            case MotionEvent.ACTION_POINTER_UP:                mode = NONE;                break;            case MotionEvent.ACTION_MOVE:                /*处理拖动*/                if (mode == DRAG) {                    if(Math.abs(stop_x-start_x-getLeft())<88 && Math.abs(stop_y - start_y-getTop())<85)                    {                        this.setPosition(stop_x - start_x, stop_y - start_y, stop_x + this.getWidth() - start_x, stop_y - start_y + this.getHeight());                        stop_x = (int) event.getRawX();                        stop_y = (int) event.getRawY();                    }                }                /*处理缩放*/                else if (mode == ZOOM) {                    if(spacing(event)>10f)                    {                        afterLenght = spacing(event);                        float gapLenght = afterLenght - beforeLenght;                        if(gapLenght == 0) {                            break;                        }                        else if(Math.abs(gapLenght)>5f)                        {                            if(gapLenght>0) {                                this.setScale(scale,BIGGER);                            }else {                                this.setScale(scale,SMALLER);                            }                            beforeLenght = afterLenght;                        }                    }                }                break;        }        return true;    }    /**     * 实现处理缩放     */    private void setScale(float temp,int flag) {        if(flag==BIGGER) {            this.setFrame(this.getLeft()-(int)(temp*this.getWidth()),                    this.getTop()-(int)(temp*this.getHeight()),                    this.getRight()+(int)(temp*this.getWidth()),                    this.getBottom()+(int)(temp*this.getHeight()));        }else if(flag==SMALLER){            this.setFrame(this.getLeft()+(int)(temp*this.getWidth()),                    this.getTop()+(int)(temp*this.getHeight()),                    this.getRight()-(int)(temp*this.getWidth()),                    this.getBottom()-(int)(temp*this.getHeight()));        }    }    /**     * 实现处理拖动     */    private void setPosition(int left,int top,int right,int bottom) {        this.layout(left,top,right,bottom);    }}