How to detect UIKeyboard "backspace" button touch on UITextField? [duplicate]

if the UITextField is empty, the shouldChangeTextInRange delegate method is not calledYou can subclass UITextField and override this method:

-(void)deleteBackward;{    [super deleteBackward];    NSLog(@"BackSpace Detected");}

since UITextField is compliant to the UITextInput protocol, this method is implemented, and you can override it to detect when backspace is pressed.Then, you can write your own protocol/delegate method to alert your custom textfield delegate if the backspace is detected.

First of all your UIViewController that references the UITextField needs to conform to the UITextFieldDelegate protocol. Then set your class as delegate to the UITextField (eg. [myTextField setDelegate:self] ). Then in your class you add the following. When a string of "" is sent as the replacementString you know it's backspace.

(BOOL)textField:(UITextField *)textField       shouldChangeCharactersInRange:(NSRange)range       replacementString:(NSString *)string{                    if ([string isEqualToString:@""]) {        NSLog(@"Backspace");                }    return YES;}

Temporary i'm inserting a zero space char on textFieldDidBeginEditing

textField.text = @"\u200B";

on backspace, it remove that chars, but graphically it's the same!

It's an hack, it works, but it hide placeholder text... not good...