I noticed that when I place a white or black UIImage into a UISegmentedControl it automatically color masks it to match the tint of the segmented control. I thought this was really cool, and was wondering if I could do this elsewhere as well. For example, I have a bunch of buttons that have a uniform shape but varied colors. Instead of making a PNG for each button, could I somehow use this color masking to use the same image for all of them but then set a tint color or something to change their actual color?


当前回答

为了在按钮上设置白色的图像(箭头图标),我们使用:

let imageOnButton = UIImage(named: "navForwardArrow")?.imageWithColor(color: UIColor.white)
button.setImage(imageOnButton, for: .normal)

已知问题:当按下按钮时,图标会失去白色。

截图:

其他回答

在Swift中,你可以这样做:

var exampleImage = UIImage(named: "ExampleImage.png")?.imageWithRenderingMode(.AlwaysTemplate)

然后在viewDidLoad中

exampleButtonOutlet.setImage(exampleImage, forState: UIControlState.Normal)

并修改颜色

exampleButtonOutlet.tintColor = UIColor(red: 1, green: 0, blue: 0, alpha: 1) //your color

编辑Xcode 8 现在你也可以在你的.xcassets to Template image中设置图像的呈现模式,然后你就不需要在var exampleImage中特别声明它了

如果你想手动屏蔽你的图像,这里是更新的代码,适用于视网膜屏幕

- (UIImage *)maskWithColor:(UIColor *)color
{
    CGImageRef maskImage = self.CGImage;
    CGFloat width = self.size.width * self.scale;
    CGFloat height = self.size.height * self.scale;
    CGRect bounds = CGRectMake(0,0,width,height);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef bitmapContext = CGBitmapContextCreate(NULL, width, height, 8, 0, colorSpace, kCGBitmapAlphaInfoMask & kCGImageAlphaPremultipliedLast);
    CGContextClipToMask(bitmapContext, bounds, maskImage);
    CGContextSetFillColorWithColor(bitmapContext, color.CGColor);
    CGContextFillRect(bitmapContext, bounds);

    CGImageRef cImage = CGBitmapContextCreateImage(bitmapContext);
    UIImage *coloredImage = [UIImage imageWithCGImage:cImage scale:self.scale orientation:self.imageOrientation];

    CGContextRelease(bitmapContext);
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(cImage);

    return coloredImage;
}

如果你有一个带有背景图像的自定义按钮。您可以设置您的按钮的色调颜色和覆盖以下图像。

在资产中选择你想设置色调的按钮背景。

在图像的属性检查器中设置渲染值为“Template image”

现在当你setbutton时。tintColor = UIColor。红色“您”按钮将以红色显示。

以上都不适合我,因为点击后色调被清除。我必须使用

button.setImageTintColor(Palette.darkGray(), for: UIControlState())

斯威夫特3:

如果你已经通过xCode界面构建器设置了你的图像,这个解决方案可能会很舒服。基本上你有一个扩展来着色图像:

extension UIImage {
    public func image(withTintColor color: UIColor) -> UIImage{
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        let context: CGContext = UIGraphicsGetCurrentContext()!
        context.translateBy(x: 0, y: self.size.height)
        context.scaleBy(x: 1.0, y: -1.0)
        context.setBlendMode(CGBlendMode.normal)
        let rect: CGRect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
        context.clip(to: rect, mask: self.cgImage!)
        color.setFill()
        context.fill(rect)
        let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return newImage
    }
}

然后,你可以准备这个UIButton扩展为特定状态的图像上色:

extension UIButton {
    func imageWith(color:UIColor, for: UIControlState) {
        if let imageForState = self.image(for: state) {
            self.image(for: .normal)?.withRenderingMode(.alwaysTemplate)
            let colorizedImage = imageForState.image(withTintColor: color)
            self.setImage(colorizedImage, for: state)
        }
    }
}

用法:

myButton.imageWith(.red, for: .normal)

P.S.(在表格单元格中工作也很好,你不需要调用setNeedDisplay()方法,由于UIImage扩展,颜色的变化是立即的。