用Android代码编写自定义可随意拖动顶点的椭圆

你可以使用Canvas绘制自定义椭圆并通过手势识别(如OnTouchListener)实现顶点的拖动。以下是简单的代码示例：

public class CustomEllipseView extends View {
    private Paint paint;
    private float centerX, centerY, radiusX, radiusY;
    private RectF ellipseBounds;

    public CustomEllipseView(Context context) {
        super(context);
        init();
    }

    private void init() {
        paint = new Paint();
        paint.setColor(Color.BLACK);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(10);
        ellipseBounds = new RectF();
        setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent event) {
                switch (event.getActionMasked()) {
                    case MotionEvent.ACTION_DOWN:
                        // 计算顶点位置并判断是否被点击
                        // 如果点击，则开始拖动
                        break;
                    case MotionEvent.ACTION_MOVE:
                        // 更新顶点位置
                        break;
                    case MotionEvent.ACTION_UP:
                        // 结束拖动
                        break;
                }
                view.invalidate();
                return true;
            }
        });
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        // 计算椭圆边界
        // ...
        canvas.drawOval(ellipseBounds, paint);
    }
}

希望对您有所帮助！