我有一个UIImage，它是一个全黑的小符号。 UIImage 设置在我拥有的自定义 UIButton 子类中。是否可以让图像对其应用tintColor，而不是黑色图像，而是将颜色更改为tintColor 的任何颜色？
我只是想避免创建新资产。
// here I want defaultImageName (that is black) to use the tintColor (that is white)
[self setImage:[UIImage imageNamed:defaultImageName] forState:UIControlStateNormal];
【问题讨论】：
标签： ios objective-c uibutton uiimage
Swift5 扩展
extension UIImage {
var template: UIImage? {
return self.withRenderingMode(.alwaysTemplate)
}
}
用法：
UIImageView
let imgView = UIImageView()
imgView.tintColor = UIColor.red
imgView.image = UIImage(named: "IMAGE_NAME_HERE")?.template
UI按钮
let button = UIButton(type: .custom)
button.tintColor = UIColor.red
button.setImage(UIImage(named: "IMAGE_NAME_HERE")?.template, for: .normal)
【讨论】：
在 iOS 13+ 上，您可以使用以下内容：
UIImage(named: "img_name")?.withTintColor(.red)
https://developer.apple.com/documentation/uikit/uiimage/3327300-withtintcolor
【讨论】：
试试这个：
func tinted(with color: UIColor) -> UIImage? {
defer { UIGraphicsEndImageContext() }
UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
color.set()
self.withRenderingMode(.alwaysTemplate).draw(in: CGRect(origin: .zero, size: self.size))
return UIGraphicsGetImageFromCurrentImageContext()
}
例如：
button.setImage(UIImage(systemName: "checkmark.circle")?.tinted(with: .systemGray), for: .normal)
【讨论】：
使用这个简单的 UIImageView 扩展
@IBInspectable var tintedColor: UIColor{
get{
return tintColor
}
set{
image = image?.withRenderingMode(.alwaysTemplate)
tintColor = newValue
}
}
【讨论】：
为什么不使用图像过滤
btn.setImage(image, for: UIControl.State.normal)
btn.setImage(image.disabled, for: UIControl.State.disabled)
使用CoreImage做图片过滤
extension UIImage
{
/// Create a grayscale image with alpha channel. Is 5 times faster than grayscaleImage().
/// - Returns: The grayscale image of self if available.
var disabled: UIImage?
{
// Create image rectangle with current image width/height * scale
let pixelSize = CGSize(width: self.size.width * self.scale, height: self.size.height * self.scale)
let imageRect = CGRect(origin: CGPoint.zero, size: pixelSize)
// Grayscale color space
let colorSpace: CGColorSpace = CGColorSpaceCreateDeviceGray()
// Create bitmap content with current image size and grayscale colorspace
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue)
if let context: CGContext = CGContext(data: nil, width: Int(pixelSize.width), height: Int(pixelSize.height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)
{
// Draw image into current context, with specified rectangle
// using previously defined context (with grayscale colorspace)
guard let cg = self.cgImage else{
return nil
}
context.draw(cg, in: imageRect)
// Create bitmap image info from pixel data in current context
if let imageRef: CGImage = context.makeImage(){
let bitmapInfoAlphaOnly = CGBitmapInfo(rawValue: CGImageAlphaInfo.alphaOnly.rawValue)
guard let context = CGContext(data: nil, width: Int(pixelSize.width), height: Int(pixelSize.height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfoAlphaOnly.rawValue) else{
return nil
}
context.draw(cg, in: imageRect)
if let mask: CGImage = context.makeImage() {
// Create a new UIImage object
if let newCGImage = imageRef.masking(mask){
// Return the new grayscale image
return UIImage(cgImage: newCGImage, scale: self.scale, orientation: self.imageOrientation)
}
}
}
}
// A required variable was unexpected nil
return nil
}
}
当然，在 Swift 5 中
【讨论】：
Swift 4，复制粘贴解决方案
@IBOutlet weak var iconImageView: UIImageView!
iconImageView.image = UIImage(imageLiteralResourceName: "myImageName").withRenderingMode(.alwaysTemplate)
iconImageView.tintColor = UIColor.red
【讨论】：
withRenderingMode(.alwaysTemplate)。示例：如果您使用UIGraphicsImageRenderer 调整图像大小。如果您将资产图像设置为模板呈现模式，这也适用。
这是我在 IOS 9 中使用 Swift 的色调和不透明度的方法 -
//apply a color to an image
//ref - http://stackoverflow.com/questions/28427935/how-can-i-change-image-tintcolor
//ref - https://www.captechconsulting.com/blogs/ios-7-tutorial-series-tint-color-and-easy-app-theming
func getTintedImage() -> UIImageView {
var image :UIImage
var imageView :UIImageView
image = UIImage(named: "someAsset")!
let size : CGSize = image.size
let frame : CGRect = CGRectMake((UIScreen.mainScreen().bounds.width-86)/2, 600, size.width, size.height)
let redCover : UIView = UIView(frame: frame)
redCover.backgroundColor = UIColor.redColor()
redCover.layer.opacity = 0.75
imageView = UIImageView();
imageView.image = image.imageWithRenderingMode(UIImageRenderingMode.Automatic)
imageView.addSubview(redCover)
return imageView
}
【讨论】：
如果您只支持 iOS 7，可以使用 tintColor 和 UIImageRenderingModeAlwaysTemplate
这篇文章涵盖了：
https://www.captechconsulting.com/blogs/ios-7-tutorial-series-tint-color-and-easy-app-theming
如果您需要支持早期版本，您可能需要考虑此线程
【讨论】：
UIImage *image = [[UIImage imageNamed:@"image.png"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];。然后将应用 tint 颜色，在 UIImageView 上设置：_imageView.tintColor = [UIColor whiteColor];