如何检查CGPoint是否在UIImageView中？

Question

在 touchesBegan:

CGPoint touch_point = [[touches anyObject] locationInView:self.view];

有几十个UIImageView,存储在一个NSMutableArray images.我想知道是否有一个内置函数来检查CGPoint(touch_point)是否在其中一个图像中,例如:

for (UIImageView *image in images) {
   // how to test if touch_point is tapped on a image?
}

谢谢

跟进:

由于未知原因,pointInside永远不会返回true.这是完整的代码.

    - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
    { 
      UITouch *touch = [touches anyObject]; 
        touch_point = [touch locationInView:self.view];
        for (UIImageView *image in piece_images) {
            if ([image pointInside:touch_point withEvent:event]) {
                image.hidden = YES;
            } else {
                image.hidden = NO;
            }
            NSLog(@"image %.0f %.0f touch %.0f %.0f", image.center.x, image.center.y, touch_point.x, touch_point.y);
        }
    } 

虽然我可以看到两点在NSLog输出中有时是相同的.

我也尝试过:

  if ([image pointInside:touch_point withEvent:nil]) 

结果是一样的.永远不会回归真实.

消除任何与图像一起使用的机会.我尝试了以下方法:

  if (YES or [image pointInside:touch_point withEvent:event])

首次点击屏幕后隐藏所有图像.

编辑2:

真的很奇怪.即使我硬编码:

        point.x = image.center.x;
        point.y = image.center.y;

代码变成:

    - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
    { 
        UITouch *touch = [touches anyObject]; 
        CGPoint point; // = [touch locationInView:self.view];
        for (UIImageView *image in piece_images) {
            point.x = image.center.x;
            point.y = image.center.y;       
            if ([image pointInside:point withEvent:event]) {
                image.hidden = YES;
                NSLog(@"YES");
            } else {
                image.hidden = NO;
                NSLog(@"NO");
            }
            NSLog(@"image %.0f %.0f touch %.0f %.0f", image.center.x, image.center.y, point.x, point.y);
        }
    }

pointInside总是回来false......

Answer 1

听起来像问题是你需要将坐标从视图的坐标转换为UIImageView坐标.您可以使用UIView的convertPoint方法.

尝试更换

if ([image pointInside:touch_point withEvent:event]) {

同

if ([image pointInside: [self.view convertPoint:touch_point toView: image] withEvent:event]) {

(请注意,您可以通过nil而不是event.)

我想这对提问者来说有点晚了,但我希望它对某人有用.