Android程式碼片段二：不規則圖形按鈕非透明區的點擊

/** * 不規則"圖形按鈕控制項" * */public class TrapezoidImageButton extends ImageButton {    public TrapezoidImageButton(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);    }    public TrapezoidImageButton(Context context, AttributeSet attrs) {    super(context, attrs);    }    public TrapezoidImageButton(Context context) {    super(context);    }        @Override    public boolean onTouchEvent(MotionEvent event) {    if (isTouchPointInView(event.getX(),event.getY())||        event.getAction() != MotionEvent.ACTION_DOWN){        return super.onTouchEvent(event);    }else{        return false;    }    }    protected boolean isTouchPointInView(float localX, float localY){    Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Config.ARGB_8888);    Canvas canvas = new Canvas(bitmap);    draw(canvas);    int x = (int)localX;    int y = (int)localY;    if (x < 0 || x >= getWidth())        return false;    if (y < 0 || y >= getHeight())        return false;    int pixel = bitmap.getPixel(x,y);    if ((pixel&0xff000000) != 0){ //點在非透明區        return true;    }else{        return false;    }    }}