我有一个名为theImageView的UIImageView, UIImage是单色的(透明背景),就像下面左边的黑色心形。我如何在iOS 7或更高的系统中,根据iOS 7+导航栏图标中使用的色调方法,以编程方式更改此图像的色调颜色?

这个方法也适用于WatchKit的Apple Watch应用程序吗?


当前回答

子类,也可以从代码和接口生成器中使用:

@implementation TintedImageView

- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        [self setup];
    }
    return self;
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if (self) {
        [self setup];
    }
    return self;
}

-(void)setup {
    self.image = [self.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
}

@end

其他回答

这里有一个类别应该可以做到这一点

@interface UIImage(Overlay)
@end

@implementation UIImage(Overlay)

- (UIImage *)imageWithColor:(UIColor *)color1
{
        UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
        CGContextRef context = UIGraphicsGetCurrentContext();
        CGContextTranslateCTM(context, 0, self.size.height);
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, kCGBlendModeNormal);
        CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
        CGContextClipToMask(context, rect, self.CGImage);
        [color1 setFill];
        CGContextFillRect(context, rect);
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        return newImage;
}
@end

所以你会这样做:

theImageView.image = [theImageView.image imageWithColor:[UIColor redColor]];

swift 3的目的

theImageView.image = theImageView.image!.withRenderingMode(.alwaysTemplate)
theImageView.tintColor = UIColor.red

斯威夫特5

重绘图像的背景和填充颜色

extension UIImage {
  func withBackground(color: UIColor, fill fillColor: UIColor) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(size, true, scale)
    
    guard let ctx = UIGraphicsGetCurrentContext(), let image = cgImage else { return self }
    defer { UIGraphicsEndImageContext() }
    
    ctx.concatenate(CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: size.height))
    
    let rect = CGRect(origin: .zero, size: size)
    
    // draw background
    ctx.setFillColor(color.cgColor)
    ctx.fill(rect)
    
    // draw image with fill color
    ctx.clip(to: rect, mask: image)
    ctx.setFillColor(fillColor.cgColor)
    ctx.fill(rect)
    
    return UIGraphicsGetImageFromCurrentImageContext() ?? self
  }
}

如果有人关心没有UIImageView的解决方案:

// (Swift 3)
extension UIImage {
    func tint(with color: UIColor) -> UIImage {
        var image = withRenderingMode(.alwaysTemplate)
        UIGraphicsBeginImageContextWithOptions(size, false, scale)
        color.set()

        image.draw(in: CGRect(origin: .zero, size: size))
        image = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return image
    }
}
let navHeight = self.navigationController?.navigationBar.frame.height;
let menuBtn = UIButton(type: .custom)
menuBtn.frame = CGRect(x: 0, y: 0, width: 45, height: navHeight!)     
menuBtn.setImage(UIImage(named:"image_name")!.withRenderingMode(.alwaysTemplate), for: .normal)        
menuBtn.tintColor = .black