How to check whether a CGPoint is inside a UIImageView?

In touchesBegan:

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

There are tens of UIImageView around, stored in a NSMutableArray images. I'd like to know is there a built-in function to check if a CGPoint (touch_point) is inside one of the images, e.g.:

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

Thanks

F开发者_开发知识库ollow up:

For unknown reason, pointInside never returns true. Here is the full code.

    - (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);
        }
    } 

although I can see the two points are sometimes identical in the NSLog output.

I also tried:

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

the result is the same. never returns a true.

To eliminate the chance of anything goes with with the images. I tried the following:

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

all images are hidden after the first click on screen.

EDIT 2:

Really weird. Even I hard coded this:

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

the code becomes:

    - (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 always returns false ...

Sounds to me like the problem is you need to convert coordinates from your view's coordinates to the UIImageView's coordinates. You can use UIView's convertPoint method.

Try replacing

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

with

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

(Note that you are allowed to pass nil instead of event.)

I guess this is a bit late for the questioner, but I hope it is of use to someone.

if ([image pointInside:touch_point withEvent:event]) {
    // Point inside
}else {
    // Point isn't inside
}

In this case event is taken from :

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;

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

    for (UIImageView *piece in piece_images) {
        CGFloat x_min = piece.center.x - (piece.bounds.size.width / 2);
        CGFloat x_max = x_min + piece.bounds.size.width;
        CGFloat y_min = piece.center.y - (piece.bounds.size.height / 2);
        CGFloat y_max = y_min + piece.bounds.size.height;
        if (point.x > x_min && point.x < x_max && point.y > y_min && point.y < y_max ) {
            piece.hidden = YES;
        } else {
            piece.hidden = NO;
        }
    }

}

too bad, I have do it myself...

it's OS 3.2, XCode 3.2.2, tried both on simulator and iPad