UIAlertView

From iPhone Development Wiki

UIAlertView is a class to display alert messages on screen. For iOS 8+, see also UIAlertController.

Showing with Undo dialog animation

Signature -(void)showWithAnimationType:(int)type;
Available in 3.0 –

Unlike all other dialogs which pops up, the Undo dialog appears by jiggling in from the side. You can do so with [alert showWithAnimationType:1].

Adding text fields

Signature -(UIAlertSheetTextField*)addTextFieldWithValue:(NSString*)defaultText label:(NSString*)promptText;
Available in 2.0 –
Signature -(UIAlertSheetTextField*)textFieldAtIndex:(NSInteger)index;
Available in 2.0 –
Signature -(UIAlertSheetTextField*)textField;
Available in 2.0 –
Signature -(NSInteger)textFieldCount;
Available in 2.0 –

You can create multiple text fields using the -addTextFieldWithValue:label: method. If you only need 1 text field, using the -textField method will automatically create only 1 for you. When the alert view has text fields, it will only be available in portrait position.

Subtitle and tagline

How subtitle and tagline look like.
Signature @property(nonatomic,copy) NSString* subtitle;
Available in 2.0 –
Signature -(void)setTaglineText:(NSString*)taglineText
Available in 2.0 –

Subtitle and tagline are two additional styles of text which you could place on an alert view. Subtitle appears below the title, and tagline appears below the message.

References