iOS 7 Programming Cookbook

1.1. Displaying Alerts with UIAlertView

Problem

You want to display a message to your users in the form of an alert. This could be used to ask them to confirm an action, to ask for their username and password, or simply to let them enter some simple text that you can use in your app.

Solution

Utilize the UIAlertView class.

Discussion

If you are an iOS user, you have most certainly already seen an alert view. Figure 1-1 depicts an example.

Figure 1-1. Example of an alert view in iOS

The best way to initialize an alert view is to use its designated initializer:

- (void) viewDidAppear:(BOOL)paramAnimated{

    [super viewDidAppear:paramAnimated];

    UIAlertView *alertView = [[UIAlertView alloc]
                              initWithTitle:@"Alert"
                              message:@"You've been delivered an alert"
                              delegate:nil
                              cancelButtonTitle:@"Cancel"
                              otherButtonTitles:@"Ok", nil];
    [alertView show];

}

When this alert view is displayed to the user, she will see something similar to that shown in Figure 1-2.

Figure 1-2. A simple alert view displayed to the user

In order to display an alert view to the user, we use the alert view’s show method. Let’s have a look at the description for each of the parameters that we passed to the initializer of the alert view:

title

The string that the alert view will display on the top when it is shown to the user. This string is ...