ios UIAlertController 自定义字体、大小、颜色

UIAlertController custom font, size, color

提问by Libor Zapletal

I am using new UIAlertController for showing alerts. I have this code:

我正在使用新的 UIAlertController 来显示警报。我有这个代码：

// nil titles break alert interface on iOS 8.0, so we'll be using empty strings
UIAlertController *alert = [UIAlertController alertControllerWithTitle: title == nil ? @"": title message: message preferredStyle: UIAlertControllerStyleAlert];


UIAlertAction *defaultAction = [UIAlertAction actionWithTitle: cancelButtonTitle style: UIAlertActionStyleCancel handler: nil];

[alert addAction: defaultAction];

UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;
[rootViewController presentViewController:alert animated:YES completion:nil];

Now I want to change title and message font, color, size and so. What's best way to do this?

现在我想更改标题和消息字体、颜色、大小等。什么是最好的方法来做到这一点？

Edit:I should insert whole code. I created category for UIView that I could show right alert for iOS version.

编辑：我应该插入整个代码。我为 UIView 创建了类别，我可以为 iOS 版本显示正确的警报。

@implementation UIView (AlertCompatibility)

+( void )showSimpleAlertWithTitle:( NSString * )title
                          message:( NSString * )message
                cancelButtonTitle:( NSString * )cancelButtonTitle
{
    float iOSVersion = [[UIDevice currentDevice].systemVersion floatValue];
    if (iOSVersion < 8.0f)
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle: title
                                                        message: message
                                                       delegate: nil
                                              cancelButtonTitle: cancelButtonTitle
                                              otherButtonTitles: nil];
        [alert show];
    }
    else
    {
        // nil titles break alert interface on iOS 8.0, so we'll be using empty strings
        UIAlertController *alert = [UIAlertController alertControllerWithTitle: title == nil ? @"": title
                                                                       message: message
                                                                preferredStyle: UIAlertControllerStyleAlert];


        UIAlertAction *defaultAction = [UIAlertAction actionWithTitle: cancelButtonTitle
                                                                style: UIAlertActionStyleCancel
                                                              handler: nil];

        [alert addAction: defaultAction];

        UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;
        [rootViewController presentViewController:alert animated:YES completion:nil];
    }
}

回答by dupuis2387

Not sure if this is against private APIs/properties but using KVC works for me on ios8

不确定这是否针对私有 API/属性，但在 ios8 上使用 KVC 对我有用

UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"Dont care what goes here, since we're about to change below" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"Presenting the great... Hulk Hogan!"];
[hogan addAttribute:NSFontAttributeName
              value:[UIFont systemFontOfSize:50.0]
              range:NSMakeRange(24, 11)];
[alertVC setValue:hogan forKey:@"attributedTitle"];



UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text" 
                                        style:UIAlertActionStyleDefault
                                        handler:^(UIAlertAction *action){
                                                    //add code to make something happen once tapped
}];
UIImage *accessoryImage = [UIImage imageNamed:@"someImage"];
[button setValue:accessoryImage forKey:@"image"];

For the record, it is possible to change alert action's font as well, using those private APIs. Again, it may get you app rejected, I have not yet tried to submit such code.

作为记录，使用这些私有 API 也可以更改警报操作的字体。同样，它可能会让你的应用程序被拒绝，我还没有尝试提交这样的代码。

let alert = UIAlertController(title: nil, message: nil, preferredStyle: .ActionSheet)

let action = UIAlertAction(title: "Some title", style: .Default, handler: nil)
let attributedText = NSMutableAttributedString(string: "Some title")

let range = NSRange(location: 0, length: attributedText.length)
attributedText.addAttribute(NSKernAttributeName, value: 1.5, range: range)
attributedText.addAttribute(NSFontAttributeName, value: UIFont(name: "ProximaNova-Semibold", size: 20.0)!, range: range)

alert.addAction(action)

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

// this has to be set after presenting the alert, otherwise the internal property __representer is nil
guard let label = action.valueForKey("__representer")?.valueForKey("label") as? UILabel else { return }
label.attributedText = attributedText

For Swift 4.2 in XCode 10 and up the last 2 lines are now:

对于 XCode 10 及更高版本中的 Swift 4.2，最后两行现在是：

guard let label = (action!.value(forKey: "__representer")as? NSObject)?.value(forKey: "label") as? UILabel else { return }
        label.attributedText = attributedText

回答by Macucula

You can change the button color by applying a tint color to an UIAlertController.

您可以通过将色调颜色应用于 UIAlertController 来更改按钮颜色。

On iOS 9, if the window tint color was set to a custom color, you have to apply the tint color right after presenting the alert. Otherwise the tint color will be reset to your custom window tint color.

在 iOS 9 上，如果窗口色调颜色设置为自定义颜色，则必须在显示警报后立即应用色调颜色。否则色调颜色将重置为您自定义的窗口色调颜色。

// In your AppDelegate for example:
window?.tintColor = UIColor.redColor()

// Elsewhere in the App:
let alertVC = UIAlertController(title: "Title", message: "message", preferredStyle: .Alert)
alertVC.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: nil))
alertVC.addAction(UIAlertAction(title: "Ok", style: .Default, handler: nil))

// Works on iOS 8, but not on iOS 9
// On iOS 9 the button color will be red
alertVC.view.tintColor = UIColor.greenColor()

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

// Necessary to apply tint on iOS 9
alertVC.view.tintColor = UIColor.greenColor()

回答by ChintaN -Maddy- Ramani

You can change color of button text using this code:

您可以使用以下代码更改按钮文本的颜色：

alertC.view.tintColor = your color;

Maybe this will help you.

也许这会帮助你。

回答by Ashok R

In Xcode 8 Swift 3.0

在 Xcode 8 Swift 3.0

@IBAction func touchUpInside(_ sender: UIButton) {

    let alertController = UIAlertController(title: "", message: "", preferredStyle: .alert)

    //to change font of title and message.
    let titleFont = [NSFontAttributeName: UIFont(name: "ArialHebrew-Bold", size: 18.0)!]
    let messageFont = [NSFontAttributeName: UIFont(name: "Avenir-Roman", size: 12.0)!]

    let titleAttrString = NSMutableAttributedString(string: "Title Here", attributes: titleFont)
    let messageAttrString = NSMutableAttributedString(string: "Message Here", attributes: messageFont)

    alertController.setValue(titleAttrString, forKey: "attributedTitle")
    alertController.setValue(messageAttrString, forKey: "attributedMessage")

    let action1 = UIAlertAction(title: "Action 1", style: .default) { (action) in
        print("\(action.title)")
    }

    let action2 = UIAlertAction(title: "Action 2", style: .default) { (action) in
        print("\(action.title)")
    }

    let action3 = UIAlertAction(title: "Action 3", style: .default) { (action) in
        print("\(action.title)")
    }

    let okAction = UIAlertAction(title: "Ok", style: .default) { (action) in
        print("\(action.title)")
    }

    alertController.addAction(action1)
    alertController.addAction(action2)
    alertController.addAction(action3)
    alertController.addAction(okAction)

    alertController.view.tintColor = UIColor.blue
    alertController.view.backgroundColor = UIColor.black
    alertController.view.layer.cornerRadius = 40

    present(alertController, animated: true, completion: nil)

}

Output

输出

回答by Robert Chen

A Swift translation of the @dupuis2387 answer. Worked out the syntax to set the UIAlertControllertitle's color and font via KVC using the attributedTitlekey.

@dupuis2387 答案的 Swift 翻译。制定了UIAlertController使用attributedTitle密钥通过 KVC设置标题颜色和字体的语法。

let message = "Some message goes here."
let alertController = UIAlertController(
    title: "", // This gets overridden below.
    message: message,
    preferredStyle: .Alert
)
let okAction = UIAlertAction(title: "OK", style: .Cancel) { _ -> Void in
}
alertController.addAction(okAction)

let fontAwesomeHeart = "\u{f004}"
let fontAwesomeFont = UIFont(name: "FontAwesome", size: 17)!
let customTitle:NSString = "I \(fontAwesomeHeart) Swift" // Use NSString, which lets you call rangeOfString()
let systemBoldAttributes:[String : AnyObject] = [ 
    // setting the attributed title wipes out the default bold font,
    // so we need to reconstruct it.
    NSFontAttributeName : UIFont.boldSystemFontOfSize(17)
]
let attributedString = NSMutableAttributedString(string: customTitle as String, attributes:systemBoldAttributes)
let fontAwesomeAttributes = [
    NSFontAttributeName: fontAwesomeFont,
    NSForegroundColorAttributeName : UIColor.redColor()
]
let matchRange = customTitle.rangeOfString(fontAwesomeHeart)
attributedString.addAttributes(fontAwesomeAttributes, range: matchRange)
alertController.setValue(attributedString, forKey: "attributedTitle")

self.presentViewController(alertController, animated: true, completion: nil)

回答by Ivan

Use UIAppearanceprotocol. Example for setting a font - create a category to extend UILabel:

使用UIAppearance协议。设置字体的示例 - 创建要扩展的类别 UILabel：

@interface UILabel (FontAppearance)
@property (nonatomic, copy) UIFont * appearanceFont UI_APPEARANCE_SELECTOR;
@end


@implementation UILabel (FontAppearance)

-(void)setAppearanceFont:(UIFont *)font {
    if (font)
        [self setFont:font];
}

-(UIFont *)appearanceFont {
    return self.font;
}

@end

And its usage:

及其用法：

UILabel * appearanceLabel = [UILabel appearanceWhenContainedIn:UIAlertController.class, nil];
[appearanceLabel setAppearanceFont:[UIFont boldSystemFontOfSize:10]]; //for example

Tested and working with style UIAlertControllerStyleActionSheet, but I guess it will work with UIAlertControllerStyleAlerttoo.

经过测试并使用 style UIAlertControllerStyleActionSheet，但我想它也可以使用UIAlertControllerStyleAlert。

P.S. Better check for class availability instead of iOS version:

PS更好地检查课程可用性而不是iOS版本：

if ([UIAlertController class]) {
    // UIAlertController code (iOS 8)
} else {
    // UIAlertView code (pre iOS 8)
}

回答by user3480295

Use UIAppearanceprotocol. Do more hacks with appearanceFontto change font for UIAlertAction.

使用UIAppearance协议。做更多的appearanceFont修改来改变UIAlertAction.

Create a category for UILabel

创建一个类别 UILabel

UILabel+FontAppearance.h

UILabel+FontAppearance.h

@interface UILabel (FontAppearance)

@property (nonatomic, copy) UIFont * appearanceFont UI_APPEARANCE_SELECTOR;

@end

UILabel+FontAppearance.m

UILabel+FontAppearance.m

@implementation UILabel (FontAppearance)

- (void)setAppearanceFont:(UIFont *)font
{
    if (self.tag == 1001) {
        return;
    }

    BOOL isBold = (self.font.fontDescriptor.symbolicTraits & UIFontDescriptorTraitBold);
    const CGFloat* colors = CGColorGetComponents(self.textColor.CGColor);

    if (self.font.pointSize == 14) {
        // set font for UIAlertController title
        self.font = [UIFont systemFontOfSize:11];
    } else if (self.font.pointSize == 13) {
        // set font for UIAlertController message
        self.font = [UIFont systemFontOfSize:11];
    } else if (isBold) {
        // set font for UIAlertAction with UIAlertActionStyleCancel
        self.font = [UIFont systemFontOfSize:12];
    } else if ((*colors) == 1) {
        // set font for UIAlertAction with UIAlertActionStyleDestructive
        self.font = [UIFont systemFontOfSize:13];
    } else {
        // set font for UIAlertAction with UIAlertActionStyleDefault
        self.font = [UIFont systemFontOfSize:14];
    }
    self.tag = 1001;
}

- (UIFont *)appearanceFont
{
    return self.font;
}

@end

Usage:

用法：

add

添加

[[UILabel appearanceWhenContainedIn:UIAlertController.class, nil] setAppearanceFont:nil];

[[UILabel appearanceWhenContainedIn:UIAlertController.class, nil] setAppearanceFont:nil];

in AppDelegate.mto make it work for all UIAlertController.

在AppDelegate.m使其所有工作UIAlertController。

回答by Gurjinder Singh

Swift 5 and 5.1. Create a separate file and put UIAlertController Customization code there

斯威夫特 5 和 5.1。创建一个单独的文件并将 UIAlertController 自定义代码放在那里

import Foundation
import  UIKit

extension UIAlertController {

  //Set background color of UIAlertController
  func setBackgroudColor(color: UIColor) {
    if let bgView = self.view.subviews.first,
      let groupView = bgView.subviews.first,
      let contentView = groupView.subviews.first {
      contentView.backgroundColor = color
    }
  }

  //Set title font and title color
  func setTitle(font: UIFont?, color: UIColor?) {
    guard let title = self.title else { return }
    let attributeString = NSMutableAttributedString(string: title)//1
    if let titleFont = font {
      attributeString.addAttributes([NSAttributedString.Key.font : titleFont],//2
        range: NSMakeRange(0, title.utf8.count))
    }
    if let titleColor = color {
      attributeString.addAttributes([NSAttributedString.Key.foregroundColor : titleColor],//3
        range: NSMakeRange(0, title.utf8.count))
    }
    self.setValue(attributeString, forKey: "attributedTitle")//4
  }

  //Set message font and message color
  func setMessage(font: UIFont?, color: UIColor?) {
    guard let title = self.message else {
      return
    }
    let attributedString = NSMutableAttributedString(string: title)
    if let titleFont = font {
      attributedString.addAttributes([NSAttributedString.Key.font : titleFont], range: NSMakeRange(0, title.utf8.count))
    }
    if let titleColor = color {
      attributedString.addAttributes([NSAttributedString.Key.foregroundColor : titleColor], range: NSMakeRange(0, title.utf8.count))
    }
    self.setValue(attributedString, forKey: "attributedMessage")//4
  }

  //Set tint color of UIAlertController
  func setTint(color: UIColor) {
    self.view.tintColor = color
  }
}

Now On any action Show Alert

Now On 任何动作 显示警报

  func tapShowAlert(sender: UIButton) {
    let alertController = UIAlertController(title: "Alert!!", message: "This is custom alert message", preferredStyle: .alert)
    // Change font and color of title
    alertController.setTitle(font: UIFont.boldSystemFont(ofSize: 26), color: UIColor.yellow)
    // Change font and color of message
    alertController.setMessage(font: UIFont(name: "AvenirNextCondensed-HeavyItalic", size: 18), color: UIColor.red)
    // Change background color of UIAlertController
    alertController.setBackgroudColor(color: UIColor.black)
    let actnOk = UIAlertAction(title: "Ok", style: .default, handler: nil)
    let actnCancel = UIAlertAction(title: "Cancel", style: .default, handler: nil)
    alertController.addAction(actnOk)
    alertController.addAction(actnCancel)
    self.present(alertController, animated: true, completion: nil)
  }

Result

结果

回答by Lucas Torquato

I'm using it.

我正在使用它。

[[UIView appearanceWhenContainedIn:[UIAlertController class], nil] setTintColor:[UIColor blueColor]];

Add one line (AppDelegate) and works for all UIAlertController.

添加一行 (AppDelegate) 并适用于所有 UIAlertController。

回答by AnthonyR

Swift 4

斯威夫特 4

Example of custom font on the title. Same things for other components such as message or actions.

标题上的自定义字体示例。其他组件的相同内容，例如消息或操作。

    let titleAttributed = NSMutableAttributedString(
            string: Constant.Strings.cancelAbsence, 
            attributes: [NSAttributedStringKey.font:UIFont(name:"FONT_NAME",size: FONT_SIZE)]
    )

    let alertController = UIAlertController(
        title: "",
        message: "",
        preferredStyle: UIAlertControllerStyle.YOUR_STYLE
    )

    alertController.setValue(titleAttributed, forKey : "attributedTitle")
    present(alertController, animated: true, completion: nil)