An object that displays an alert message to the user.
- iOS 8.0+
- tvOS 9.0+
Use this class to configure alerts and action sheets with the message that you want to display and the actions from which to choose. After configuring the alert controller with the actions and style you want, present it using the
present(_: method. UIKit displays alerts and action sheets modally over your app's content.
In addition to displaying a message to a user, you can associate actions with your alert controller to give the user a way to respond. For each action you add using the
add method, the alert controller configures a button with the action details. When the user taps that action, the alert controller executes the block you provided when creating the action object. Listing 1 shows how to configure an alert with a single action.
When configuring an alert with the
UIAlert style, you can also add text fields to the alert interface. The alert controller lets you provide a block for configuring your text fields prior to display. The alert controller maintains a reference to each text field so that you can access its value later.