获取CGContext绘制的Arc中的触摸点

Question

我使用下面的代码绘制了这么多弧:

CGContextAddArc(context,
                        e.x,
                        e.y,
                        Distance/2,
                        M_PI+angle1,
                        angle1,
                        aClock); 
        CGContextStrokePath(context)

现在我希望当我触摸任何拱形时,我想要检测到哪个弧被触摸过

我怎样才能做到这一点？

Answer 1

你可以这样做：

1.将弧添加到路径中，

_path = CGPathCreateMutable();
CGPathAddArc(_path, NULL, e.x, e.y, Distance/2, M_PI + angle1, angle1, aClock);
CGContextAddPath(context, _path);
CGContextStrokePath(context);

2.重写touchesBegan:withEvent:

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSSet *allTouches = [event allTouches];
    UITouch *touch = [allTouches anyObject];
    CGPoint point = [touch locationInView:[touch view]];

    if (CGPathContainsPoint(_path, NULL, point, NO)) {
        NSLog(@"point:(%f, %f), Touch arc.", point.x, point.y);
    }
    else {
        NSLog(@"point:(%f, %f), Touch other.", point.x, point.y);
    }
}

您会看到“触摸弧”。记录触摸弧时的情况。