填充对象的相交区域 [英] Fill intersection area of objects

问题描述

我想使用Android Canvas填充矩形和圆形的相交区域，如下图所示:

I want to fill the intersection area of a rectangle and a circle using Android Canvas like in the image below:

我该如何实现?

更新: 这是我的代码

public static class MyView extends View {
    private Paint paint;
    public MyView(Context context) {
        super(context);
        init();
    }
    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }
    public MyView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }
    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public MyView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init();
    }
    private void init() {
        paint = new Paint();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(5);
        paint.setColor(Color.BLUE);
        canvas.drawRect(getRect(), paint);
        paint.setColor(Color.GRAY);
        canvas.drawCircle(250,150, 100, paint);
    }

    public Rect getRect() {
        return new Rect(100,100,400,200);
    }

}

现在:

在这种情况下，通缉结果是这样的:

in this case, The Wanted result is this :

感谢您的帮助

推荐答案

您需要查看android.graphics.Path类.

如果可以使用Path定义形状，则可以使用canvas.drawPath()绘制形状.

If you can define your shapes with Paths, then you can draw them using canvas.drawPath().

Path有一个称为op()的方法，可用于获取两条路径的交点，如下所示:

Path has a method called op() that you can use to get the intersection of two paths, like this:

    Path square = ...
    Path circle = ...
    Path intersect = circle.op(square, Op.INTERSECT);

在Paint.Style为FILL的情况下，您可以为两个形状的交点着色.

With a Paint.Style of FILL, you can color the intersection of the two shapes.

这篇关于填充对象的相交区域的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！