突出显示/选定状态问题的 UIButton 背景颜色

Question

I've a UIButton and I've created an extension to add background color for different state.

I'm using the following code:

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)
    }
}


// Set Button Title and background color for different states
    self.donateButton.setBackgroundColor(UIColor.redColor(), forState: .Normal)
    self.donateButton.setTitleColor(UIColor.whiteColor(), forState: .Normal)
    self.donateButton.setBackgroundColor(UIColor.greenColor(), forState: .Highlighted)
    self.donateButton.setTitleColor(UIColor.whiteColor(), forState: .Highlighted)
    self.donateButton.setBackgroundColor(UIColor.greenColor(), forState: .Selected)
    self.donateButton.setTitleColor(UIColor.whiteColor(), forState: .Selected)

My Problem is that it is not picking up proper UIButton background color and title color for highlighted/selected state.

Answer 1

我发现了这个问题， UIButton被设置为System 。我只是将其更改为Custom ，它开始按预期工作。

Answer 2

Update 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)
    }

}

Event Button Action Show Touch On Highlight

Answer 3

Swift 5, IOS 13+

extension UIButton {

  func setBackgroundColor(_ color: UIColor, for forState: UIControl.State) {
    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 4

The reason it does not work is that you have not set the correct state: you are missing the [ .highlighted, .selected ] state, and so it falls back to plain .normal .

When both isSelected and isHighlighted are true, UIKit looks explicitly for the state-combination of the two, and will not accept any of them individually.

The original code extended with the missing state (and updated to valid syntax in Swift 5):

self.donateButton.setBackgroundColor(.green, for: [ .highlighted, .selected ])
self.donateButton.setTitleColor(.white, for: [ .highlighted, .selected ])

Answer 5

When your UIButton is selected. If you focus on the button, it will not highlight the button as state .Highlighted . If it is not selected, it will highlight it as your will. For it regards you have background image in your button, it will use the default effect to highlight a image. If you want to change the state to .Selected , you have to set the variable selected of UIButton to true.

Answer 6

要实现自定义按钮照明，您需要： - 在故事板中设置您想要看到的背景颜色和 alpha，当按钮被按下时 - 在初始化时，将背景和 alpha 设置为未按下的按钮 - 实施按钮的三种方法（Touch Down / Touch Up Side / Touch Drag Outside） - 在其中，更改按钮照明