UIAlertController custom font, size, color

Question

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

// 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?

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

@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];
    }
}

Answer 1

You can use an external library like PMAlertController without using workaround, where you can substitute Apple's uncustomizable UIAlertController with a super customizable alert.

Compatible with Xcode 8, Swift 3 and Objective-C

Features:

• [x] Header View
• [x] Header Image (Optional)
• [x] Title
• [x] Description message
• [x] Customizations: fonts, colors, dimensions & more
• [x] 1, 2 buttons (horizontally) or 3+ buttons (vertically)
• [x] Closure when a button is pressed
• [x] Text Fields support
• [x] Similar implementation to UIAlertController
• [x] Cocoapods
• [x] Carthage
• [x] Animation with UIKit Dynamics
• [x] Objective-C compatibility
• [x] Swift 2.3 & Swift 3 support

Answer 2

In Swift 4.1 and Xcode 9.4.1

//Displaying alert with multiple actions and custom font ans size
let alert = UIAlertController(title: "", message: "", preferredStyle: .alert)

let titFont = [NSAttributedStringKey.font: UIFont(name: "ArialHebrew-Bold", size: 15.0)!]
let msgFont = [NSAttributedStringKey.font: UIFont(name: "Avenir-Roman", size: 13.0)!]

let titAttrString = NSMutableAttributedString(string: "Title Here", attributes: titFont)
let msgAttrString = NSMutableAttributedString(string: "Message Here", attributes: msgFont)

alert.setValue(titAttrString, forKey: "attributedTitle")
alert.setValue(msgAttrString, forKey: "attributedMessage")

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

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

let okAction = UIAlertAction(title: "Ok", style: .default) { (action) in
    print("\(String(describing: action.title))")
}
alert.addAction(action1)
alert.addAction(action2)
alert.addAction(okAction)

alert.view.tintColor = UIColor.blue
alert.view.layer.cornerRadius = 40
// //If required background colour 
// alert.view.backgroundColor = UIColor.white

DispatchQueue.main.async(execute: {
    self.present(alertController, animated: true)
})

Answer 3

Here is an extension for Swift 4.1 and Xcode 9.4.1:

extension UIAlertController{

func addColorInTitleAndMessage(color:UIColor,titleFontSize:CGFloat = 18, messageFontSize:CGFloat = 13){

    let attributesTitle = [NSAttributedStringKey.foregroundColor: color, NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: titleFontSize)]
    let attributesMessage = [NSAttributedStringKey.foregroundColor: color, NSAttributedStringKey.font: UIFont.systemFont(ofSize: messageFontSize)]
    let attributedTitleText = NSAttributedString(string: self.title ?? "", attributes: attributesTitle)
    let attributedMessageText = NSAttributedString(string: self.message ?? "", attributes: attributesMessage)

    self.setValue(attributedTitleText, forKey: "attributedTitle")
    self.setValue(attributedMessageText, forKey: "attributedMessage")

}}

Answer 4

A Swift translation of the @dupuis2387 answer. Worked out the syntax to set the UIAlertController title's color and font via KVC using the attributedTitle key.

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)

Answer 5

I just use this kind of demand, seemingly and system, details are slightly different, so we are ... OC realized Alert and Sheet popup window encapsulation.

Often encountered in daily development need to add a figure to Alert or change a button color, such as "simple" demand, today brings a and system components of highly similar and can fully meet the demand of customized packaging components.

Github:https://github.com/ReverseScale/RSCustomAlertView

Answer 6

To change the color of one button like CANCEL to the red color you can use this style property called UIAlertActionStyle.destructive :

let prompt = UIAlertController.init(title: "Reset Password", message: "Enter Your E-mail :", preferredStyle: .alert)
        let okAction = UIAlertAction.init(title: "Submit", style: .default) { (action) in
              //your code
}

let cancelAction = UIAlertAction.init(title: "Cancel", style: UIAlertActionStyle.destructive) { (action) in
                //your code
        }
        prompt.addTextField(configurationHandler: nil)
        prompt.addAction(okAction)
        prompt.addAction(cancelAction)
        present(prompt, animated: true, completion: nil);