android 自定義View圓圈拖動

問題：
1 . 累加問題：“點擊坐標”坐標在移動時必須改變位置，不然將導致累加過載
2. 圓形改變問題，每次重繪時圓必將改變位置
3. 圖片平移：圓在移動時只要

public class MovingBlockView extends View {

    //畫筆
    Paint paint = new Paint();
    Region circleRegion;
    Path circlePath;
    private boolean Move;

    /*圓心*/
    private float x = 300;
    private float y = 300;

    /*點擊坐標*/
    private float ClickX = 0;
    private float ClickY = 0;

    /*圓心移動距離*/
    private float moveX;
    private float moveY;


    /*
    * 圓形拖到問題：
    * 1 ，累加問題：“點擊坐標”坐標在移動時必須改變位置，不然將導致累加過載
    *  2. 圓形改變問題，每次重繪時圓必將改變位置
    * 3.圖片平移：圓在移動時只要
    *
    * */
    public MovingBlockView(Context context) {
        this(context, null);
    }

    public MovingBlockView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MovingBlockView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        /*mPaint = new Paint();
        mPaint.setColor(Color.RED);*/

        paint.setColor(Color.RED);
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        circlePath = new Path();
        x = x + moveX;
        y = y + moveY;
        circlePath.addCircle(x, y, 300, Path.Direction.CW);
        Region region = new Region(0, 0, getMeasuredWidth(), getMeasuredHeight());
        circleRegion = new Region();
  
        circleRegion.setPath(circlePath, region);

        canvas.drawPath(circlePath, paint);
        canvas.drawLine(x + moveX, 0, x + moveX, getHeight(), paint);
        canvas.drawLine(0, y + moveY, getWidth(), y + moveY, paint);

//        canvas.drawCircle();


    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int action = event.getAction();
        if (action == MotionEvent.ACTION_DOWN) {
            boolean contains = circleRegion.contains((int) event.getX(), (int) event.getY());
            if (contains) {
//                Toast.makeText(getContext(), "點擊了圓", Toast.LENGTH_LONG).show();
                Move = true;
                ClickX = event.getX();
                ClickY = event.getY();
                Log.d(TAG, "ACTION_DOWN: " + ClickX);
                Log.d(TAG, "ACTION_DOWN: " + ClickY);
            }
        } else if (action == MotionEvent.ACTION_UP) {
            x = x + moveX;
            y = y + moveY;
            Move = false;
            Log.d(TAG, "ACTION_UP: ");
        } else if (action == MotionEvent.ACTION_MOVE) {
            if (Move) {
                Log.d(TAG, "ACTION_MOVE: ");
                moveX = event.getX() - ClickX;
                moveY = event.getY() - ClickY;
                ClickX = event.getX();
                ClickY = event.getY();
                Log.d(TAG, "ACTION_MOVE: " + moveX);
                Log.d(TAG, "ACTION_MOVE: " + moveY);
                invalidate();
            }
        }
        return super.onTouchEvent(event);
    }
}