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
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。
其他回答
let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red
如果你在设置UIButton。tintColor by UIColor(r:g:b:alpha:),记住值除以255。这些RGB值应该在0和1之间。
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
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
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:
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