如何在iOS和WatchKit中更改图像tintColor

Question

我有一个名为“theImageView”的UIImageView，UIImage为单色（透明背景），就像下面的左黑心一样。如何根据iOS 7+导航栏图标中使用的色调方法在iOS 7或更高版本中以编程方式更改此图像的色调？这种方法也适用于Apple Watch应用程序的WatchKit吗？

Answer 1

这是一个应该做的技巧

@interface UIImage(Overlay)

@end

@implementation UIImage(Overlay)

- (UIImage *)imageWithColor:(UIColor *)color1

{

        UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);

        CGContextRef context = UIGraphicsGetCurrentContext();

        CGContextTranslateCTM(context, 0, self.size.height);

        CGContextScaleCTM(context, 1.0, -1.0);

        CGContextSetBlendMode(context, kCGBlendModeNormal);

        CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);

        CGContextClipToMask(context, rect, self.CGImage);

        [color1 setFill];

        CGContextFillRect(context, rect);

        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

        UIGraphicsEndImageContext();

        return newImage;

}

@end

所以你会这样做：

theImageView.image = [theImageView.image imageWithColor:[UIColor redColor]];

Answer 2

我必须在Swift中使用extension。

我以为我会分享我是如何做到的：

extension UIImage {

    func imageWithColor(color1: UIColor) -> UIImage {

        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)

        color1.setFill()

        let context = UIGraphicsGetCurrentContext() as CGContextRef

        CGContextTranslateCTM(context, 0, self.size.height)

        CGContextScaleCTM(context, 1.0, -1.0);

        CGContextSetBlendMode(context, CGBlendMode.Normal)

        let rect = CGRectMake(0, 0, self.size.width, self.size.height) as CGRect

        CGContextClipToMask(context, rect, self.CGImage)

        CGContextFillRect(context, rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext() as UIImage

        UIGraphicsEndImageContext()

        return newImage

    }

}

用法：

theImageView.image = theImageView.image.imageWithColor(UIColor.redColor())

斯威夫特4

extension UIImage {

    func imageWithColor(color1: UIColor) -> UIImage {

        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)

        color1.setFill()

        let context = UIGraphicsGetCurrentContext()

        context?.translateBy(x: 0, y: self.size.height)

        context?.scaleBy(x: 1.0, y: -1.0)

        context?.setBlendMode(CGBlendMode.normal)

        let rect = CGRect(origin: .zero, size: CGSize(width: self.size.width, height: self.size.height))

        context?.clip(to: rect, mask: self.cgImage!)

        context?.fill(rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        return newImage!

    }

}

用法：

theImageView.image = theImageView.image?.imageWithColor(color1: UIColor.red)