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change UIAlertcontroller background Color

Ok so I have this alert that I am using and I want the background of it to be black not grey like it is. I have managed to change the colour of the text for the title and the message but not the background colour. Well to the desired colour I want. I have changed it to green blue and white, but not black. When I try to change it to black it turns grey. Any suggestions will help and be appreciated. I tried this here How to change the background color of the UIAlertController? and that is how I got to where I am now.

Here is what I have going now:

func showAlert(title:String, message:String) {

    //Set up for the title color
    let attributedString = NSAttributedString(string: title, attributes: [
        NSFontAttributeName : UIFont.systemFontOfSize(15), //your font here,
        NSForegroundColorAttributeName : UIColor.whiteColor()
        ])
    //Set up for the Message Color
    let attributedString2 = NSAttributedString(string: message, attributes: [
        NSFontAttributeName : UIFont.systemFontOfSize(15), //your font here,
        NSForegroundColorAttributeName : UIColor.whiteColor()
        ])

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

    alert.setValue(attributedString, forKey: "attributedTitle")
    alert.setValue(attributedString2, forKey: "attributedMessage")
    //alert.view.tintColor = UIColor.whiteColor()
    let dismissAction = UIAlertAction(title: "Dismiss", style: .Destructive, handler: nil)
        alert.addAction(dismissAction)
    self.presentViewController(alert, animated: true, completion: nil)
    //set the color of the Alert
    let subview = alert.view.subviews.first! as UIView
    let alertContentView = subview.subviews.first! as UIView
    alertContentView.backgroundColor = UIColor.blackColor()
    //alertContentView.backgroundColor = UIColor.greenColor()
    //Changes is to a grey color :( 
    /*
    alertContentView.backgroundColor = UIColor(
        red: 0,
        green: 0,
        blue: 0,
        alpha: 1.0)
    //Also another Grey Color Not batman black
    */

    //alertContentView.backgroundColor = UIColor.blueColor()
    //turns into a purple



}

Swift 4.1 :

This is the best way works for me :

func testAlert(){
    let alert = UIAlertController(title: "Let's See ..",message: "It Works!", preferredStyle: .alert)
    let dismissAction = UIAlertAction(title: "Dismiss", style: .default, handler: nil)

    // Accessing alert view backgroundColor :
    alert.view.subviews.first?.subviews.first?.subviews.first?.backgroundColor = UIColor.green

    // Accessing buttons tintcolor :
    alert.view.tintColor = UIColor.white

    alert.addAction(dismissAction)
    present(alert, animated: true, completion:  nil)
}

测试图像

try this

Swift2 and below

let subview :UIView = alert.view.subviews. first! as UIView
let alertContentView = subview.subviews. first! as UIView
alertContentView.backgroundColor = UIColor.blackColor()

Objective -C

UIView *subView = alertController.view.subviews.firstObject; //firstObject
UIView *alertContentView = subView.subviews.firstObject; //firstObject
[alertContentView setBackgroundColor:[UIColor darkGrayColor]];

alertContentView.layer.cornerRadius = 5;

updated answer swift 3 and above

   let alert = UIAlertController(title: "validate",message: "Check the process", preferredStyle: .alert)
    let dismissAction = UIAlertAction(title: "Dismiss", style: .destructive, handler: nil)
    alert.addAction(dismissAction)
    self.present(alert, animated: true, completion:  nil)
    // change the background color
    let subview = (alert.view.subviews.first?.subviews.first?.subviews.first!)! as UIView
    subview.layer.cornerRadius = 1
    subview.backgroundColor = UIColor(red: (195/255.0), green: (68/255.0), blue: (122/255.0), alpha: 1.0)

output

iPhone

在此处输入图片说明

iPad

在此处输入图片说明

Swift 5
Write just one line of code using UIAlertController extension.

alertController.setBackgroundColor(color: UIColor.black)

Full documentation: http://www.swiftdevcenter.com/change-font-text-color-and-background-color-of-uialertcontroller/

extension UIAlertController {

    //Set background color of UIAlertController
    func setBackgroundColor(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 setTitlet(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 message = self.message else { return }
        let attributeString = NSMutableAttributedString(string: message)
        if let messageFont = font {
            attributeString.addAttributes([NSAttributedString.Key.font : messageFont],
                                          range: NSMakeRange(0, message.utf8.count))
        }

        if let messageColorColor = color {
            attributeString.addAttributes([NSAttributedString.Key.foregroundColor : messageColorColor],
                                          range: NSMakeRange(0, message.utf8.count))
        }
        self.setValue(attributeString, forKey: "attributedMessage")
    }

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

For Objective C, the below code works like charm.

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Save changes?" message:nil preferredStyle:UIAlertControllerStyleAlert];

UIView *firstSubview = alertController.view.subviews.firstObject;

UIView *alertContentView = firstSubview.subviews.firstObject;

for (UIView *subSubView in alertContentView.subviews) { //This is main catch
    subSubView.backgroundColor = [UIColor blueColor]; //Here you change background
}

Due to a known bug ( https://openradar.appspot.com/22209332 ), the accepted solution doesn't work on iOS 9.

See my full answer here: https://stackoverflow.com/a/37737212/1781087

In case someone wants to have an opaque white background color he can do this with this one liner:

UIVisualEffectView.appearance(whenContainedInInstancesOf: [UIAlertController.classForCoder() as! UIAppearanceContainer.Type]).backgroundColor = UIColor.white

Note however this will work properly only with white color as other colors will appear differently because of the default visual effect.

let subview = (alert.view.subviews.first?.subviews.first?.subviews.first!)! as UIView subview.layer.cornerRadius = 1 subview.backgroundColor = UIColor.white

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