Custom UIAlertController – iOS (Objective-C)
Creating a custom UIAlertController helps you to show a popup in your iOS application whenever you need to show a simple warning/information popup. It is an embedded iOS library and that means you do not need to install any 3rd party library.
A classic popup in mobile applications contains 3 parts: title, content and buttons. You set title according the purpose of the popup, set content as message and set buttons to get action.
Create a Screen
Open your project, create a new and empty ViewController and add a simple button to trigger the popup.
Connect this button to ViewController.m file as IBOutlet by selecting “Assistant Editor” at top-left. Drag button with right-click from view to ViewController.m file.
Create a Simple AlertController
Then, create a simple UIAlertController with a title, a message and a button.
- (IBAction)dialogButton:(id)sender {
UIAlertController *controller = [UIAlertController alertControllerWithTitle:@"AlertController Title" message:@"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed pellentesque ullamcorper sollicitudin." preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *buttonOk = [UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
[self actionOk];
}];
[controller addAction:buttonOk];
[self presentViewController:controller animated:YES completion:nil];
}
-(void) actionOk {
//your "ok" action here...
}
If you want to add another button, for example a cancel button, just add it like “Ok” button.
//UIAlertActionStyleDestructive gives you a red colored button
UIAlertAction *buttonCancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDestructive handler:^(UIAlertAction * _Nonnull action) {
}];
[controller addAction:buttonCancel];
Add More Buttons and TextField
You can add more than 2 buttons to your AlertController by repeating add action method.
UIAlertAction *button1 = [UIAlertAction actionWithTitle:@"Button One" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
[self actionOne];
}];
UIAlertAction *button2 = [UIAlertAction actionWithTitle:@"Button Two" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
[self actionTwo];
}];
[controller addAction:button1];
[controller addAction:button2];
This is a basic view of UIAlertController in an iOS application. You can customize it, of course. For example, you can change colors, fonts, size or you can add a text field in your popup. Let’s start with adding a text field to our popup. In iOS, UIAlertController has a method to add a textfield into the window and it is very simple as a line of code.
[controller addTextFieldWithConfigurationHandler:^(UITextField *textField) {}];
And you can customize it too with…
[controller addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"PlaceHolder";
textField.textColor = [UIColor blueColor];
textField.keyboardType = UIKeyboardTypeDefault;
}];
Customize AlertController
As the last customizing, lets change colors of some views in this popup.
NSMutableAttributedString *titleTxt = [[NSMutableAttributedString alloc] initWithString:@"AlertController Title"];
[titleTxt addAttribute:NSFontAttributeName
value:[UIFont systemFontOfSize:22.0]
range:NSMakeRange(0, titleTxt.length)];
[titleTxt addAttribute:NSForegroundColorAttributeName
value:UIColor.brownColor
range:NSMakeRange(0, 15)];
[titleTxt addAttribute:NSForegroundColorAttributeName
value:UIColor.purpleColor
range:NSMakeRange(16, 5)];
[controller setValue:titleTxt forKey:@"attributedTitle"];
controller.view.tintColor = UIColor.darkGrayColor;
[controller addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"PlaceHolder";
textField.textColor = [UIColor blueColor];
textField.keyboardType = UIKeyboardTypeDefault;
}];
That’s all. Maybe it is not a good idea to change all colors in popup like this example 🙂 Be certain of your colors and app theme in a harmony.
Final Work: Custom AlertController
To get the latest version of popup in this tutorial, see the code below.
//
// ViewController.m
// HelloWorld
//
// Created by Kağan Kartal on 11.11.2018.
// Copyright © 2018 CoffeeBreakCodes. All rights reserved.
//
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (IBAction)dialogButton:(id)sender {
UIAlertController *controller = [UIAlertController alertControllerWithTitle:@"AlertController Title"
message:@"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed pellentesque ullamcorper sollicitudin."
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *button1 = [UIAlertAction actionWithTitle:@"Button One" style:UIAlertActionStyleDefault
handler:^(UIAlertAction * _Nonnull action) {
[self actionOne];
}];
UIAlertAction *button2 = [UIAlertAction actionWithTitle:@"Button Two" style:UIAlertActionStyleDefault
handler:^(UIAlertAction * _Nonnull action) {
[self actionTwo];
}];
//UIAlertActionStyleDestructive gives you a red colored button
UIAlertAction *buttonCancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDestructive
handler:^(UIAlertAction * _Nonnull action) {
}];
NSMutableAttributedString *titleTxt = [[NSMutableAttributedString alloc] initWithString:@"AlertController Title"];
[titleTxt addAttribute:NSFontAttributeName
value:[UIFont systemFontOfSize:22.0]
range:NSMakeRange(0, titleTxt.length)];
[titleTxt addAttribute:NSForegroundColorAttributeName
value:UIColor.brownColor
range:NSMakeRange(0, 15)];
[titleTxt addAttribute:NSForegroundColorAttributeName
value:UIColor.purpleColor
range:NSMakeRange(16, 5)];
[controller setValue:titleTxt forKey:@"attributedTitle"];
controller.view.tintColor = UIColor.darkGrayColor;
[controller addTextFieldWithConfigurationHandler:^(UITextField *textField) {
textField.placeholder = @"PlaceHolder";
textField.textColor = [UIColor blueColor];
textField.keyboardType = UIKeyboardTypeDefault;
}];
[controller addAction:button1];
[controller addAction:button2];
[controller addAction:buttonCancel];
[self presentViewController:controller animated:YES completion:nil];
}
-(void) actionOne {
}
-(void) actionTwo {
}
@end
©Coffee Break Codes – Custom Alert Controller – iOS (Objective-C)