UIAlertController 修改字体颜色

Question

UIAlertController 修改字体颜色

24

这是我创建 UIAlertController 的代码：

    // Create the alert controller
    var alertController = UIAlertController(title: "Are you sure you want to call \(self.number)?", message: "", preferredStyle: .Alert)

    // Create the actions
    var okAction = UIAlertAction(title: "Call", style: UIAlertActionStyle.Default) {
        UIAlertAction in
        var url:NSURL = NSURL(string: "tel://\(self.number)")!
        UIApplication.sharedApplication().openURL(url)
    }

    var cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel) {
        UIAlertAction in

    }

    // Add the actions
    alertController.addAction(okAction)
    alertController.addAction(cancelAction)

    // Present the controller
    self.presentViewController(alertController, animated: true, completion: nil)

我无法弄清如何更改取消和通话操作的文本颜色。标题文本当前为黑色，取消和通话按钮为白色。我想使它们全部变为黑色，以提高可见性。有什么建议吗？谢谢！

- leerob

10个回答

9

皮尤什的回答对我最有帮助，但是这里有一些针对Swift 3的调整以及分别更改标题和消息的方法。

标题:

alert.setValue(NSAttributedString(string: alert.message, attributes: [NSFontAttributeName : UIFont.systemFont(ofSize: 29, weight: UIFontWeightMedium), NSForegroundColorAttributeName : UIColor.red]), forKey: "attributedTitle")

信息：

alert.setValue(NSAttributedString(string: alert.message, attributes: [NSFontAttributeName : UIFont.systemFont(ofSize: 29, weight: UIFontWeightMedium), NSForegroundColorAttributeName : UIColor.red]), forKey: "attributedMessage")

字体大小大是因为我实际上需要在tvOS上使用，它在tvOS和iOS上都表现良好。

- CodyMace

标题：alert.setValue(NSAttributedString(string: alert.title, attributes: [NSFontAttributeName : UIFont.systemFont(ofSize: 29, weight: UIFontWeightMedium), NSForegroundColorAttributeName : UIColor.red]), forKey: "attributedTitle") - Asmita

8

Swift 4.2

一种做法是在UIAlertController上进行扩展，这样你的应用程序中所有的警报都将具有相同的色调颜色。但它会以红色显示破坏性操作。

 extension UIAlertController{
        open override func viewDidLayoutSubviews() {
            super.viewDidLayoutSubviews()
           self.view.tintColor = .yourcolor
        }
    }

- Karlicic Bojan

7

下面的代码可以改变UIAlertView标题的颜色。

  let alert = UIAlertController(title: messageTitle, message: messageText, preferredStyle: UIAlertControllerStyle.Alert)

  alert.setValue(NSAttributedString(string: messageTitle, attributes: [NSFontAttributeName : UIFont.systemFontOfSize(17),NSForegroundColorAttributeName : UIColor.redColor()]), forKey: "attributedTitle")

  alert.addAction(UIAlertAction(title: buttonText, style: UIAlertActionStyle.Default, handler: nil))

  parent.presentViewController(alert, animated: true, completion: nil)

如果您想更改按钮颜色，请在当前视图控制器之后添加以下代码。

  alert.view.tintColor = UIColor.redColor()

- Piyush Sanepara

3

以下是关于Swift 4的更新，以Cody的答案为基础：

为警告标题设置颜色：

alert.setValue(NSAttributedString(string: alert.title!, attributes: [NSAttributedStringKey.font : UIFont.systemFont(ofSize: 17, weight: UIFont.Weight.medium), NSAttributedStringKey.foregroundColor : UIColor.blue]), forKey: "attributedTitle")

设置警报信息的颜色：

alert.setValue(NSAttributedString(string: alert.message, attributes: [NSAttributedStringKey.font : UIFont.systemFont(ofSize: 17, weight: UIFont.Weight.Medium), NSAttributedStringKey.foregroundColor : UIColor.green]), forKey: "attributedMessage")

根据https://developer.apple.com/documentation/foundation/nsattributedstring/key，此内容与编程有关。

- podomunro

1

只需要一个修改，您在颜色示例中遗漏了.font。 - jbm

3

在Swift 5和XCode 11.1及更高版本中，警告标题的颜色为：

alert.setValue(NSAttributedString(string: alert.title!, attributes: [NSAttributedString.Key.font : UIFont.systemFont(ofSize: 25, weight: UIFont.Weight.medium), NSAttributedString.Key.foregroundColor : UIColor.red]), forKey: "attributedTitle")

警告信息的颜色：

alert.setValue(NSAttributedString(string: alert.message!, attributes: [NSAttributedString.Key.font : UIFont.systemFont(ofSize: 20,weight: UIFont.Weight.medium),NSAttributedString.Key.foregroundColor :UIColor.black]), forKey: "attributedMessage")

- MannaICT13

1

我曾经遇到同样的问题，花了很多时间尝试找到最佳方法来改变iOS 9和iOS 10+的颜色，因为它是以不同的方式实现的。

最终我为UIViewController创建了一个扩展。在扩展中，我添加了一个自定义函数，几乎等同于默认函数“present”，但执行颜色修复。这是我的解决方案。适用于Swift 3+，针对iOS 9及以上版本的项目：

extension UIViewController {
    /// Function for presenting AlertViewController with fixed colors for iOS 9
    func presentAlert(alert: UIAlertController, animated flag: Bool, completion: (() -> Swift.Void)? = nil){
        // Temporary change global colors
        UIView.appearance().tintColor = UIColor.red // Set here whatever color you want for text
        UIApplication.shared.keyWindow?.tintColor = UIColor.red // Set here whatever color you want for text

        //Present the controller
        self.present(alert, animated: flag, completion: {
            // Rollback change global colors
            UIView.appearance().tintColor = UIColor.black // Set here your default color for your application.
            UIApplication.shared.keyWindow?.tintColor = UIColor.black // Set here your default color for your application.
            if completion != nil {
                completion!()
            }
        })
    }
}

要使用此固定功能，您只需调用此函数而不是默认的 present 函数。例如：

self.presentAlert(alert: alert, animated: true)

相同的解决方案，但适用于UIActivityViewController：

extension UIViewController {
    /// Function for presenting UIActivityViewController with fixed colors for iOS 9 and 10+
    func presentActivityVC(vc: UIActivityViewController, animated flag: Bool, completion: (() -> Swift.Void)? = nil) {
        // Temporary change global colors for changing "Cancel" button color for iOS 9 and 10+
        if UIDevice.current.systemVersion.range(of: "9.") != nil {
            UIApplication.shared.keyWindow?.tintColor = ColorThemes.alertViewButtonTextColor
        } else {
            UILabel.appearance().textColor = ColorThemes.alertViewButtonTextColor
        }

        self.present(vc, animated: flag) {
            // Rollback for changing global colors for changing "Cancel" button color for iOS 9 and 10+
            if UIDevice.current.systemVersion.range(of: "9.") != nil {
                UIApplication.shared.keyWindow?.tintColor = ColorThemes.tintColor
            } else {
                UILabel.appearance().textColor = ColorThemes.textColorNormal
            }
            if completion != nil {
                completion!()
            }
        }
    }
}

我希望这能帮助到某些人，并节省大量时间。因为这样详细的回答并没有节省我的时间 :)

- DJ-Glock

1

在iOS 9.0之前，您可以像这样简单地更改基础视图的tintColor：

alertController.view.tintColor = UIColor.redColor()

然而，由于iOS 9中引入的一个漏洞，你只能做到以下两点：

Change the app tintColor in the AppDelegate.

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject : AnyObject]?) -> Bool {
    self.window.tintColor = UIColor.redColor()
    return true
}

Reapply the color in the completion block.

self.presentViewController(alert, animated: true, completion: {() -> Void in
    alert.tintColor = UIColor.redColor()
})

请看我在这里的另一个答案：https://dev59.com/CJfga4cB1Zd3GeqPCeMN#37737212

- guidev

1

试试这个

alert.setValue(NSAttributedString(string: alert.message, attributes: [NSFontAttributeName : UIFont.systemFont(ofSize: 29, weight: UIFontWeightMedium), NSForegroundColorAttributeName : UIColor.red]), forKey: "attributedTitle")

- Nabeel ali

0

func showAlertOnVC(title: String,btnTitle:String, btnSubTitle:String, message: String, VC: UIViewController? , getcompleted: @escaping((_ confrmation: Bool)-> ())) {
        guard let vc = VC  else {
            return
        }
        let alert = UIAlertController(title: title , message: message, preferredStyle: (UIDevice.current.userInterfaceIdiom == UIUserInterfaceIdiom.pad )  ? .alert : .alert)
        
        alert.view.tintColor = UIColor.green
        let confirmBtn = UIAlertAction(title: btnTitle, style: .default, handler: {_ in
            getcompleted(true)
        })
        let cancelBtn = UIAlertAction(title: btnSubTitle, style: .cancel, handler: {_ in
            getcompleted(false)
        })
        cancelBtn.setValue(UIColor.red, forKey: "titleTextColor")
        alert.addAction(confirmBtn)
        alert.addAction(cancelBtn)
        vc.present(alert, animated: true, completion: nil)
    }

- Sasinderan N

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- leerob · Accepted Answer

24

经过一些尝试和错误，我发现这个方法可行。希望这对未来的Swift新手有所帮助！

alertController.view.tintColor = UIColor.blackColor()

- leerob

这在第一次弹出警告时对我起作用了。但是在点击按钮后，它们又改回了默认颜色。从我在其他地方阅读的内容来看，我认为这个问题可能是iOS 9中的新问题。 - peacetype

因为这在iOS 9中不起作用，所以这里有一个解决方案来设置UIAlertController按钮的tintColor：https://dev59.com/Yl8d5IYBdhLWcg3wxUjC#32636878 - peacetype