iPhone keyboard, Done button and resignFirstResponder

nevan king picture nevan king · May 13, 2010 · Viewed 109.3k times · Source

This is probably a dumb question, but I can't find the answer in the docs. Did the "Done" button on the pop-up keyboard always cause the keyboard to disappear? I see a lot of code around the web like this:

- (BOOL)textFieldShouldReturn:(UITextField *)theTextField {
    [theTextField resignFirstResponder];
    return YES;
}

When I press the "Done" button, the keyboard pops down and the UITextField resigns first responder.

I'm presuming that pressing the "Done" button didn't used to cause a UITextField to resignFirstResponder, but that behavior changed at some time.

I'm debugging on OS 3.0 - 3.1.3

Answer

nevan king picture nevan king · May 13, 2010

I made a small test project with just a UITextField and this code

#import <UIKit/UIKit.h>
@interface TextFieldTestViewController : UIViewController
<UITextFieldDelegate>
{
    UITextField *textField;
}
@property (nonatomic, retain) IBOutlet UITextField *textField;
@end

#import "TextFieldTestViewController.h"
@implementation TextFieldTestViewController
@synthesize textField;

- (void)viewDidLoad
{
    [self.textField setDelegate:self];
    [self.textField setReturnKeyType:UIReturnKeyDone];
    [self.textField addTarget:self
                  action:@selector(textFieldFinished:)
        forControlEvents:UIControlEventEditingDidEndOnExit];
    [super viewDidLoad];
}
- (IBAction)textFieldFinished:(id)sender
{
    // [sender resignFirstResponder];
}

- (void)dealloc {
    [super dealloc];
}
@end

The text field is an unmodified UITextField dragged onto the NIB, with the outlet connected.
After loading the app, clicking in the text field brings up the keyboard. Pressing the "Done" button makes the text field lose focus and animates out the keyboard. Note that the advice around the web is to always use [sender resignFirstResponder] but this works without it.