如何在状态中设置UIButton背景颜色：UIControlState.Highlighted在Swift中

Question

我可以设置按钮的背景颜色，但我无法弄清楚如何设置UIControlState.Highlighted的背景颜色。它甚至可能吗？还是我需要沿着setBackgroundImage路走？

Answer 1

如果有人停下来，另一种方式可能更容易，如果它是你需要不止一次...我为UIButton写了一个简短的扩展，它的工作正常：

对于Swift 3

extension UIButton {
    func setBackgroundColor(color: UIColor, forState: UIControlState) {
        UIGraphicsBeginImageContext(CGSize(width: 1, height: 1))
        CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(), color.CGColor)
        CGContextFillRect(UIGraphicsGetCurrentContext(), CGRect(x: 0, y: 0, width: 1, height: 1))
        let colorImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        self.setBackgroundImage(colorImage, forState: forState)
    }
}

对于Swift 4

extension UIButton {
    func setBackgroundColor(color: UIColor, forState: UIControl.State) {
        self.clipsToBounds = true  // add this to maintain corner radius
        UIGraphicsBeginImageContext(CGSize(width: 1, height: 1))
        if let context = UIGraphicsGetCurrentContext() {
            context.setFillColor(color.cgColor)
            context.fill(CGRect(x: 0, y: 0, width: 1, height: 1))
            let colorImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            self.setBackgroundImage(colorImage, for: forState)
        }
    }
}

你像setBackgroundImage一样使用它：

yourButton.setBackgroundColor(color: UIColor.white, forState: UIControl.State.highlighted)

Answer 2

对于Swift 3+语法，语法更改为@winterized extension

extension UIButton {
    func setBackgroundColor(color: UIColor, forState: UIControlState) {
        UIGraphicsBeginImageContext(CGSize(width: 1, height: 1))
        UIGraphicsGetCurrentContext()!.setFillColor(color.cgColor)
        UIGraphicsGetCurrentContext()!.fill(CGRect(x: 0, y: 0, width: 1, height: 1))
        let colorImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        self.setBackgroundImage(colorImage, for: forState)
    }}

Answer 3

以下是一种方法。两个IBActions。一个按下按钮时控制背景颜色，一个在释放时控制。

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var button: UIButton!

    @IBAction func buttonClicked(sender: AnyObject) { //Touch Up Inside action
        button.backgroundColor = UIColor.whiteColor()
    }

    @IBAction func buttonReleased(sender: AnyObject) { //Touch Down action
        button.backgroundColor = UIColor.blueColor()

    }

    override func viewDidLoad() {
        super.viewDidLoad()

    }
}

在添加句点后查看按钮的自动完成选项时，可以设置背景颜色，但不能设置指定的状态。您只能设置背景图像。当然，如果你结婚这样做而不是使用我上面显示的方法，你可以使用setbackgroundImageForState属性加载所需颜色的图像作为背景图像。

Answer 4

Swift 4版本的this solution：

extension UIButton {

    func setBackgroundColor(_ color: UIColor, for state: UIControlState) {

        UIGraphicsBeginImageContext(CGSize(width: 1, height: 1))
        UIGraphicsGetCurrentContext()!.setFillColor(color.cgColor)
        UIGraphicsGetCurrentContext()!.fill(CGRect(x: 0, y: 0, width: 1, height: 1))
        let colorImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        setBackgroundImage(colorImage, for: state)
    }
}

Answer 5

更新Swift 4

 extension UIButton {

    func setBackgroundColor(color: UIColor, forState: UIControlState) {

        UIGraphicsBeginImageContext(CGSize(width: 1, height: 1))
        UIGraphicsGetCurrentContext()!.setFillColor(color.cgColor)
        UIGraphicsGetCurrentContext()!.fill(CGRect(x: 0, y: 0, width: 1, height: 1))
        let colorImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()


        self.setBackgroundImage(colorImage, for: forState)
    }

事件按钮操作

显示触摸突出显示

Answer 6

对于接受的答案，Swift 4+兼容性：

extension UIButton {

  /// Sets the background color to use for the specified button state.
  func setBackgroundColor(color: UIColor, forState: UIControlState) {

    let minimumSize: CGSize = CGSize(width: 1.0, height: 1.0)

    UIGraphicsBeginImageContext(minimumSize)

    if let context = UIGraphicsGetCurrentContext() {
      context.setFillColor(color.cgColor)
      context.fill(CGRect(origin: .zero, size: minimumSize))
    }

    let colorImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    self.clipsToBounds = true
    self.setBackgroundImage(colorImage, for: forState)
  }
}

兼容SwiftLint并修复损坏的自动布局/角半径的错误。

Answer 7

似乎这里没有人提到过使用Key Value Observation，但这是另一种方法。

这样做而不是在此处选择其他答案的原因是您不需要一直创建新图像，也不需要关注将图像分配给按钮的辅助效果（例如cornerRadius效果）。

但是你需要为观察者创建一个类，他们负责存储不同的背景颜色并在observeValue()方法中应用它们。

public class ButtonHighlighterObserver: NSObject {

  var observedButton:UIButton? = nil

  var backgroundColor: UIColor            = UIColor.white
  var backgroundHighlightColor: UIColor   = UIColor.gray

  public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {

    // Perform background color changes when highlight state change is observed
    if keyPath == "highlighted", object as? UIButton === observedButton {
        observedButton!.backgroundColor = observedButton!.isHighlighted ? self.backgroundHighlightColor : self.backgroundColor
    }
}

}

然后，您需要做的就是在操作期间管理addObserver / removeObserver：

// Add observer to button's highlighted value
button.addObserver(anObserver, forKeyPath: "highlighted", options: [.new], context: nil)
anObserver.observedButton = button

// ...

// And at deinit time, be sure you remove the observer again
anObserver.observedButton?.removeObserver(item, forKeyPath: "highlighted")
anObserver.observedButton = nil

Answer 8

我们可以使用运行时属性做同样的事情吗？

@IBInspectable var HighlightedBackground: Bool {
            get {
                return true
            }
           set {
            layer.backgroundColor = Common.sharedInstance.OrangeColor.CGColor
                print("highlighted state")
            }
        }

Answer 9

为什么不？

@implementation UIButton (Color)

- (void) setBackgroundColor:(UIColor*)color forState:(UIControlState)state
{
    [self setBackgroundImage:[UIImage.alloc initWithCIImage:[CIImage imageWithColor:[CIColor colorWithCGColor:color.CGColor]]] forState:state];
}

@end