Enabling an uibarbuttomitem when at least one char is written in a uitextfield

franium · 02-25-2011, 08:17 AM

Hi,

I would to enable the done button on the navbar (in a modal view) when the user write at least a char in a uitextfield. Using textFieldDidEndEditing: enables the button when the previous uitextfield resigns first responder (so with the zero chars in the current uitextfield). textFieldShouldBeginEditing: is called when the textfield becomes the first responder.
The solution could be

Code:

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

but neither

Code:

 [self.navigationItem.rightBarButtonItem setEnabled:YES];

or

Code:

[doneButton setEnabled:YES]; //doneButton is an IBOutlet tied to my Done UIBarButtonItem in IB

work.
Any ideas?
Thanks,

Fran

franium · 02-25-2011, 09:21 AM

It's strange... I've added a property for doneButton (and synthesize) and it worked, then I remove the property, coming back to the old code and it works also so. But now I've another problem. This code:

Code:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
	if (textField == password) {
		if (textField.text.length > 0) {
			doneButton.enabled = YES;
		} else {
			doneButton.enabled = NO;
		}
	}
	return YES;
}

enables the button when the text length is >0, but it disables the button when the chars are 0 and 2.
I don't understand this behaviour.

franium · 02-25-2011, 10:47 AM

Quote:

Originally Posted by franium

It's strange... I've added a property for doneButton (and synthesize) and it worked, then I remove the property, coming back to the old code and it works also so. But now I've another problem. This code:

Code:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
	if (textField == password) {
		if (textField.text.length > 0) {
			doneButton.enabled = YES;
		} else {
			doneButton.enabled = NO;
		}
	}
	return YES;
}

enables the button when the text length is >0, but it disables the button when the chars are 0 and 2.
I don't understand this behaviour.

I resolved with this check:

Code:

if (textField.text.length >= 0) {
			doneButton.enabled = YES;
		} 
		if (string.length == 0 && textField.text.length == 1) {
			doneButton.enabled = NO;
		}

franium · 02-25-2011, 12:16 PM

Quote:

Originally Posted by franium

Hi,

I would to enable the done button on the navbar (in a modal view) when the user write at least a char in a uitextfield. Using textFieldDidEndEditing: enables the button when the previous uitextfield resigns first responder (so with the zero chars in the current uitextfield). textFieldShouldBeginEditing: is called when the textfield becomes the first responder.
The solution could be

Code:

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

but neither

Code:

 [self.navigationItem.rightBarButtonItem setEnabled:YES];

or

Code:

[doneButton setEnabled:YES]; //doneButton is an IBOutlet tied to my Done UIBarButtonItem in IB

work.
Any ideas?
Thanks,

Fran

Moreover, I haven't set the delegate for the navbar