IOS/objective-C : Change tint of an image view

Question

我想在用户触摸它时更改 ImageView 的颜色。我不需要它来改变很多。但是，我希望它变成蓝色。我找到了以下代码来更改渐变，但它没有任何效果。实际上，我不需要渐变，只需要一种色调。将不胜感激任何建议。

 UIView *snapshot = [[UIImageView alloc] initWithImage:image];
        snapshot.layer.masksToBounds = NO;
          CAGradientLayer *gradient = [CAGradientLayer layer];

        gradient.colors = @[(id)[UIColor redColor].CGColor, (id)[UIColor blackColor].CGColor];

        [snapshot.layer insertSublayer:gradient atIndex:0];

Answer 1

一种简单且非侵入性的方法是在 ImageView 中添加半透明覆盖。然后可以在按下和释放按钮时显示和隐藏它。

- (void)indicatedImageViewPressed:(UIImageView *)imageView on:(BOOL)on {
    UIView *overlay = [imageView viewWithTag:1]; // See if already created
    if (overlay == nil) {
        overlay = [[UIView alloc] initWithFrame:imageView.bounds];
        overlay.tag = 1; // Mark view to find it next time
        overlay.backgroundColor = [UIColor colorWithRed:0.0 green:0.0 blue:1.0 alpha:0.3]; // Your color overlay goes here
        [imageView addSubview:overlay];
    }
    overlay.hidden = !on;
}