How to implement highlighting on UIImage like UIButton does when tapped?
I need to replicate the effect that the UIButton does on an image when tapped, the highlighting. See:
The original PNG is a square with alpha background. When I set it as UIButton's image it automatically apply an effect on the non-alpha pixels of the image.
开发者_开发问答How to do this effect?
You could achieve this with a simple category on UIImage:
@interface UIImage (Tint)
- (UIImage *)tintedImageUsingColor:(UIColor *)tintColor;
@end
@implementation UIImage (Tint)
- (UIImage *)tintedImageUsingColor:(UIColor *)tintColor {
UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
CGRect drawRect = CGRectMake(0, 0, self.size.width, self.size.height);
[self drawInRect:drawRect];
[tintColor set];
UIRectFillUsingBlendMode(drawRect, kCGBlendModeSourceAtop);
UIImage *tintedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return tintedImage;
}
@end
For the effect shown above, you'd pass something like [UIColor colorWithWhite:0.0 alpha:0.3]
as the tintColor parameter (experiment with the alpha value).
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