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)

你可以子类化UIButton并创建forState。

colourButton.h

#import <UIKit/UIKit.h>

@interface colourButton : UIButton

-(void)setBackgroundColor:(UIColor *)backgroundColor forState:(UIControlState)state;

@end

颜色按钮.m

#import "colourButton.h"

@implementation colourButton
{
    NSMutableDictionary *colours;
}

-(id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];

    // If colours does not exist
    if(!colours)
    {
        colours = [NSMutableDictionary new];  // The dictionary is used to store the colour, the key is a text version of the ENUM
        colours[[NSString stringWithFormat:@"%lu", UIControlStateNormal]] = (UIColor*)self.backgroundColor;  // Store the original background colour
    }

    return self;
}

-(void)setBackgroundColor:(UIColor *)backgroundColor forState:(UIControlState)state
{
    // If it is normal then set the standard background here
    if(state & UIControlStateNormal)
    {
        [super setBackgroundColor:backgroundColor];
    }

    // Store the background colour for that state
    colours[[NSString stringWithFormat:@"%lu", state]]= backgroundColor;
}

-(void)setHighlighted:(BOOL)highlighted
{
    // Do original Highlight
    [super setHighlighted:highlighted];

    // Highlight with new colour OR replace with orignial
    if (highlighted && colours[[NSString stringWithFormat:@"%lu", UIControlStateHighlighted]])
    {
        self.backgroundColor = colours[[NSString stringWithFormat:@"%lu", UIControlStateHighlighted]];
    }
    else
    {
        self.backgroundColor = colours[[NSString stringWithFormat:@"%lu", UIControlStateNormal]];
    }
}

-(void)setSelected:(BOOL)selected
{
    // Do original Selected
    [super setSelected:selected];

    // Select with new colour OR replace with orignial
    if (selected && colours[[NSString stringWithFormat:@"%lu", UIControlStateSelected]])
    {
        self.backgroundColor = colours[[NSString stringWithFormat:@"%lu", UIControlStateSelected]];
    }
    else
    {
        self.backgroundColor = colours[[NSString stringWithFormat:@"%lu", UIControlStateNormal]];
    }
}

@end

注释(这是一个例子，我知道有问题，这里有一些)

我已经使用了一个NSMutableDictionay来存储每个状态的UIColor，我必须为键做一个讨厌的文本转换，因为UIControlState不是一个很好的直Int。如果它在哪里，你可以init一个数组与许多对象，并使用状态作为一个索引。

因此，你有很多困难，例如一个选中&禁用按钮，一些更多的逻辑是需要的。

另一个问题是，如果你试图同时设置多种颜色，我没有尝试过一个按钮，但如果你能这样做，它可能不会工作

 [btn setBackgroundColor:colour forState:UIControlStateSelected & UIControlStateHighlighted];

我假设这是StoryBoard，没有init和initWithFrame如果你需要，可以添加它们。

Swift中一个方便的通用扩展:

extension UIButton {
    private func imageWithColor(color: UIColor) -> UIImage {
        let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()

        CGContextSetFillColorWithColor(context, color.CGColor)
        CGContextFillRect(context, rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image
    }

    func setBackgroundColor(color: UIColor, forUIControlState state: UIControlState) {
        self.setBackgroundImage(imageWithColor(color), forState: state)
    }
}

斯威夫特3.0

extension UIButton {
    private func imageWithColor(color: UIColor) -> UIImage? {
        let rect = CGRect(x: 0.0, y: 0.0, width: 1.0, height: 1.0)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()

        context?.setFillColor(color.cgColor)
        context?.fill(rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image
    }

    func setBackgroundColor(_ color: UIColor, for state: UIControlState) {
        self.setBackgroundImage(imageWithColor(color: color), for: state)
    }
}

class CustomButton: UIButton {

    override var isHighlighted: Bool {
        didSet {
            if (isHighlighted) {
                alpha = 0.5
            }
            else {
                alpha = 1
            }            
        }
    }

}

你可以通过简单地使用UIButton上的setBackgroundImage方法，并使用这个UIImage(color:)初始化项来使用一张图像，像这样轻松地更改高亮显示/选中的按钮背景颜色:

btn.setBackgroundImage(UIImage(color: .black), for: .highlighted)

注意:

如果你为圆角边框使用cornerRadius属性，你必须将clipsToBounds设置为true，这样所选的背景颜色将保留圆角半径值。

细节

Xcode 11.1 (11A1027)， Swift 5

解决方案

import UIKit

extension UIColor {
    func createOnePixelImage() -> UIImage? {
        let size = CGSize(width: 1, height: 1)
        UIGraphicsBeginImageContext(size)
        defer { UIGraphicsEndImageContext() }
        guard let context = UIGraphicsGetCurrentContext() else { return nil }
        context.setFillColor(cgColor)
        context.fill(CGRect(origin: .zero, size: size))
        return UIGraphicsGetImageFromCurrentImageContext()
    }
}

extension UIButton {
    func setBackground(_ color: UIColor, for state: UIControl.State) {
        setBackgroundImage(color.createOnePixelImage(), for: state)
    }
}

使用

button.setBackground(.green, for: .normal)