extension UIButton {
    func setBackgroundColor(color: UIColor, forState: UIControl.State) {
        let size = CGSize(width: 1, height: 1)
        UIGraphicsBeginImageContext(size)
        let context = UIGraphicsGetCurrentContext()
        context?.setFillColor(color.cgColor)
        context?.fill(CGRect(origin: CGPoint.zero, size: size))
        let colorImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        setBackgroundImage(colorImage, for: forState)
    }

}

谢谢@Maverick

解决方案Swift 3+没有子类化。

extension UIButton {
  func setBackgroundColor(_ color: UIColor, for state: UIControlState) {
    let rect = CGRect(x: 0, y: 0, width: 1, height: 1)
    UIGraphicsBeginImageContext(rect.size)
    color.setFill()
    UIRectFill(rect)
    let colorImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    setBackgroundImage(colorImage, for: state)
  }
}

有了这个扩展，它很容易管理不同状态的颜色，它会自动褪色你的正常颜色，如果高亮的颜色是不提供的。

button.setBackgroundColor(.red, for: .normal)

更新:

使用UIButtonBackgroundColor Swift库。

OLD:

使用下面的帮助工具创建一个1px x 1px的图像，灰度填充颜色:

UIImage *image = ACUTilingImageGray(248/255.0, 1);

或RGB填充颜色:

UIImage *image = ACUTilingImageRGB(253/255.0, 123/255.0, 43/255.0, 1);

然后，使用该图像设置按钮的背景图像:

[button setBackgroundImage:image forState:UIControlStateNormal];

助手

#pragma mark - Helpers

UIImage *ACUTilingImageGray(CGFloat gray, CGFloat alpha)
{
    return ACUTilingImage(alpha, ^(CGContextRef context) {
        CGContextSetGrayFillColor(context, gray, alpha);
    });
}

UIImage *ACUTilingImageRGB(CGFloat red, CGFloat green, CGFloat blue, CGFloat alpha)
{
    return ACUTilingImage(alpha, ^(CGContextRef context) {
        CGContextSetRGBFillColor(context, red, green, blue, alpha);
    });
}

UIImage *ACUTilingImage(CGFloat alpha, void (^setFillColor)(CGContextRef context))
{
    CGRect rect = CGRectMake(0, 0, 0.5, 0.5);
    UIGraphicsBeginImageContextWithOptions(rect.size, alpha == 1, 0);
    CGContextRef context = UIGraphicsGetCurrentContext();
    setFillColor(context);
    CGContextFillRect(context, rect);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

注意:ACU是我的Cocoa Touch静态库称为Acani Utilities的类前缀，其中AC是Acani, U是Utilities。

一个更紧凑的解决方案(基于@aleksejs-mjaliks的答案):

Swift +四分之三的:

override var isHighlighted: Bool {
    didSet {
        backgroundColor = isHighlighted ? .lightGray : .white
    }
}

斯威夫特2:

override var highlighted: Bool {
    didSet {
        backgroundColor = highlighted ? UIColor.lightGrayColor() : UIColor.whiteColor()
    }
}

如果你不想覆盖，这是一个更新版本的@timur-bernikowich的答案(Swift 4.2):

extension UIButton {
  func setBackgroundColor(_ color: UIColor, forState controlState: UIControl.State) {
    let colorImage = UIGraphicsImageRenderer(size: CGSize(width: 1, height: 1)).image { _ in
      color.setFill()
      UIBezierPath(rect: CGRect(x: 0, y: 0, width: 1, height: 1)).fill()
    }
    setBackgroundImage(colorImage, for: controlState)
  }
}

不需要重写高亮显示为computed属性。你可以使用属性观察者来触发背景颜色的变化:

override var highlighted: Bool {
    didSet {
        backgroundColor = highlighted ? UIColor.lightGrayColor() : UIColor.whiteColor()
    }
}

斯威夫特4

override open var isHighlighted: Bool {
    didSet {
        backgroundColor = isHighlighted ? UIColor.lightGray : UIColor.white
    }
}

下面的uiimage扩展将生成具有指定颜色参数的图像对象。

extension UIImage {
    static func imageWithColor(tintColor: UIColor) -> UIImage {
        let rect = CGRect(x: 0, y: 0, width: 1, height: 1)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0)
        tintColor.setFill()
        UIRectFill(rect)
        let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return image
       }
    }

按钮的示例用法可以应用于按钮对象，如下所示:

setupButton.setBackgroundImage(UIImage.imageWithColor(tintColor: UIColor(displayP3Red: 232/255, green: 130/255, blue: 121/255, alpha: 1.0)), for: UIControlState.highlighted)

setupButton.setBackgroundImage(UIImage.imageWithColor(tintColor: UIColor(displayP3Red: 255/255, green: 194/255, blue: 190/255, alpha: 1.0)), for: UIControlState.normal)