cancelButtonIndex
The index number of the cancel button.
Declaration
var cancelButtonIndex: Int { get set }Discussion
Button indices start at 0. The default value of this property is normally -1, which indicates that no cancel button has been set. However, a cancel button may be created and set automatically by the init(title:delegate:cancelButtonTitle:destructiveButtonTitle:) method. If you use that method to create a cancel button, you should not change the value of this property.
When presenting an action sheet on an iPad, there are times when you should not include a cancel button. For more information on when you should include a cancel button, see the class overview or iOS Human Interface Guidelines.