custom UIButton with skewed area in iPhone

Question

I want to have a button on a screen with this image. this image is transparent from its corners as you can see here.

UIButton *btn=[UIButton buttonWithType:UIButtonTypeCustom];
[btn setFrame:CGRectMake(xCo, yCo, kImageSizeWidth, kImageSizeHeight)];
[btn setImage:[UIImage imageNamed:@"aboveImg.png"] forState:UIControlStateNormal];
[btn addTarget:self action:@selector(btnTapped:) forControlEvents:UIControlEventTouchDown];

But the button tap is recognized out side image & i don't want that kind of functionality.

I mean tap must be recognized only when it is tapped within image not outside image.

How is that possible ?

Thanks in advance for sharing your great knowledge.

Sagar.

Answer 1

You can subclass that UIButton, then override its -pointInside:withEvent: function to something similar to

-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event {
   if (point is in that rhombus)
     return YES;
   else
     return NO;
}