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
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
其他回答
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:
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。
从ios7开始,在UIImage上有一个新的方法来指定渲染模式。使用渲染模式UIImageRenderingModeAlwaysTemplate将允许图像颜色由按钮的色调颜色控制。
objective - c
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [[UIImage imageNamed:@"image_name"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[button setImage:image forState:UIControlStateNormal];
button.tintColor = [UIColor redColor];
斯威夫特
let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red
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;
}
自定义按钮以各自的图像颜色显示。在故事板中将按钮类型设置为“System”(或者在代码中设置为UIButtonTypeSystem),将以默认的色调呈现按钮的图像。
(在iOS9, Xcode 7.3上测试)
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