我有一个名为theImageView的UIImageView, UIImage是单色的(透明背景),就像下面左边的黑色心形。我如何在iOS 7或更高的系统中,根据iOS 7+导航栏图标中使用的色调方法,以编程方式更改此图像的色调颜色?

这个方法也适用于WatchKit的Apple Watch应用程序吗?


当前回答

Swift 3版本的扩展答案从模糊

func imageWithColor(color: UIColor) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
    color.setFill()

    let context = UIGraphicsGetCurrentContext()! as CGContext
    context.translateBy(x: 0, y: self.size.height)
    context.scaleBy(x: 1.0, y: -1.0);
    context.setBlendMode(.normal)

    let rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height) as CGRect
    context.clip(to: rect, mask: self.cgImage!)
    context.fill(rect)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()! as UIImage
    UIGraphicsEndImageContext()

    return newImage
}

其他回答

在故事板和图像资产中。你也可以改变这两个:

更新渲染模式为模板图像

更新视图中的色调颜色。

试试这个

http://robots.thoughtbot.com/designing-for-ios-blending-modes

or

- (void)viewDidLoad
{
[super viewDidLoad];

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 30, 300, 50)];
label.numberOfLines = 0;
label.font = [UIFont systemFontOfSize:13];
label.text = @"These checkmarks use the same gray checkmark image with a tintColor applied to the image view";
[self.view addSubview:label];

[self _createImageViewAtY:100 color:[UIColor purpleColor]];
}

- (void)_createImageViewAtY:(int)y color:(UIColor *)color {
UIImage *image = [[UIImage imageNamed:@"gray checkmark.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
CGRect frame = imageView.frame;
frame.origin.x = 100;
frame.origin.y = y;
imageView.frame = frame;

if (color)
    imageView.tintColor = color;

[self.view addSubview:imageView];
}

Swift 3版本的扩展答案从模糊

func imageWithColor(color: UIColor) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
    color.setFill()

    let context = UIGraphicsGetCurrentContext()! as CGContext
    context.translateBy(x: 0, y: self.size.height)
    context.scaleBy(x: 1.0, y: -1.0);
    context.setBlendMode(.normal)

    let rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height) as CGRect
    context.clip(to: rect, mask: self.cgImage!)
    context.fill(rect)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()! as UIImage
    UIGraphicsEndImageContext()

    return newImage
}

这是我的UIImage扩展,你可以直接使用changeTintColor函数的图像。

extension UIImage {

    func changeTintColor(color: UIColor) -> UIImage {
        var newImage = self.withRenderingMode(.alwaysTemplate)
        UIGraphicsBeginImageContextWithOptions(self.size, false, newImage.scale)
        color.set()
        newImage.draw(in: CGRect(x: 0.0, y: 0.0, width: self.size.width, height: self.size.height))
        newImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return newImage
    }

    func changeColor(color: UIColor) -> UIImage {
        let backgroundSize = self.size
        UIGraphicsBeginImageContext(backgroundSize)
        guard let context = UIGraphicsGetCurrentContext() else {
            return self
        }
        var backgroundRect = CGRect()
        backgroundRect.size = backgroundSize
        backgroundRect.origin.x = 0
        backgroundRect.origin.y = 0

        var red: CGFloat = 0
        var green: CGFloat = 0
        var blue: CGFloat = 0
        var alpha: CGFloat = 0
        color.getRed(&red, green: &green, blue: &blue, alpha: &alpha)
        context.setFillColor(red: red, green: green, blue: blue, alpha: alpha)
        context.translateBy(x: 0, y: backgroundSize.height)
        context.scaleBy(x: 1.0, y: -1.0)
        context.clip(to: CGRect(x: 0.0, y: 0.0, width: self.size.width, height: self.size.height),
                 mask: self.cgImage!)
        context.fill(backgroundRect)

        var imageRect = CGRect()
        imageRect.size = self.size
        imageRect.origin.x = (backgroundSize.width - self.size.width) / 2
        imageRect.origin.y = (backgroundSize.height - self.size.height) / 2

        context.setBlendMode(.multiply)
        context.draw(self.cgImage!, in: imageRect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage!
    }

}

示例用法如下

let image = UIImage(named: "sample_image")
imageView.image = image.changeTintColor(color: UIColor.red)

你可以使用change changeColor函数来改变图像的颜色

另外,对于以上的答案,在iOS 13及以后有一个干净的方法

let image = UIImage(named: "imageName")?.withTintColor(.white, renderingMode: .alwaysTemplate)