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

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())

其他回答

正如Ric已经在他的帖子中提到的,你可以在代码中设置渲染模式,你也可以直接在图像目录中这样做,见下面所附的图像。只需要设置渲染为模板图像

注意,我在使用iOS 7和这种方法时遇到过问题。如果你也使用iOS 7,你可能也想在代码中完成,就像这里描述的。

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;
}

如果你在ios15之后到达这里,你使用的是新的UIButton。配置api,那么您可能需要通过imageColorTransformer来实现。

看起来是这样的:

configuration.imageColorTransformer = UIConfigurationColorTransformer { _ in .green }

为了方便,你可以创建一个扩展:

extension UIButton.Configuration {
    func imageColor(_ color: UIColor) -> UIButton.Configuration {
        var configuration = self
        configuration.imageColorTransformer = UIConfigurationColorTransformer { _ in color }
        return configuration
    }
}

// Usage:
configuration = configuration.imageColor(.green)

与其他答案一样,图像本身必须在Xcode资产中“渲染为模板图像”,或者在code image. withrenderingmode (.alwaysTemplate)中


小贴士: 如果您想在按钮高亮显示时改变图像颜色,该怎么办?然后你的配置扩展看起来像这样:

func imageColor(whenNormal: UIColor,
                whenHighlighted: UIColor,
                isHighlighted: Bool) -> UIButton.Configuration {
    var configuration = self
    configuration.imageColorTransformer = UIConfigurationColorTransformer { _ in
        isHighlighted ? whenHighlighted : whenNormal
    }
    return configuration
}

这个本身必须从configurationUpdateHandler上下文中调用,就像这样:

someButton.configurationUpdateHandler = { button in
    guard var configuration = button.configuration else {  return }
    configuration.image = UIImage(named: "some_image")
    configuration = configuration.imageColor(whenNormal: .green,
                                             whenHighlighted: .green.withAlphaComponent(0.7),
                                             isHighlighted: button.isHighlighted)
    button.configuration = configuration
}

注意,您还可以在configurationUpdateHandler中根据按钮状态定义不同的映像。

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())

我有一个问题,掩蔽图像在突出显示的状态。我不希望发生这种事。如果你有同样的问题,看看这个:adjustsImageWhenHighlighted = false