Scroll view when editing not working correctly - iphone

Question

I am trying to make a UIScrollView scroll when the user starts editing a UITextField and the text field is hidden by the keyboard. I am using an example from the following thread.
How to make a UITextField move up when keyboard is present
I have four UITextFields in my view. When the keyboard is shown for the first time the view does not scroll automatically. If I click another text field with the keyboard shown, the UIScrollView scrolls as intended.
Hiding the keyboard (by tapping the "Done" button) and tapping a UITextField again the same issue occurs: the UIScrollView does not scroll at first but when changing focus to another text field it scrolls perfectly.
Can anyone please help me?
In viewDidLoad I set the size of the scrollView
keyboardIsShown = NO;
CGSize scrollContentSize = CGSizeMake(320, 350);
self.scrollView.contentSize = scrollContentSize;
I register for the keyboard notifications in viewWillAppear
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:self.view.window];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:self.view.window];
Then I unregister in viewWillDisappear
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
The following two methods are called by the notifications.
- (void)keyboardWillShow:(NSNotification *)n {
if (keyboardIsShown) {
return;
}
NSDictionary *userInfo = [n userInfo];
NSValue *boundsValue = [userInfo objectForKey:UIKeyboardFrameBeginUserInfoKey];
CGSize keyboardSize = [boundsValue CGRectValue].size;
CGRect viewFrame = self.scrollView.frame;
viewFrame.size.height -= (keyboardSize.height - 50);
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.3];
[self.scrollView setFrame:viewFrame];
[UIView commitAnimations];
keyboardIsShown = YES;
}
- (void)keyboardWillHide:(NSNotification *)n {
NSDictionary *userInfo = [n userInfo];
NSValue *boundsValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
CGSize keyboardSize = [boundsValue CGRectValue].size;
CGRect viewFrame = self.scrollView.frame;
viewFrame.size.height += (keyboardSize.height - 50);
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.3];
[self.scrollView setFrame:viewFrame];
[UIView commitAnimations];
keyboardIsShown = NO;
}

Answer 1

If you want to show the textfeild when keyboard is visible then use the code below. Don't go with the scrollview. If it is compulsory to use a scrollView then neglect this answer.
#define kOFFSET_FOR_KEYBOARD 280.0
- (void)keyboardWillHide:(NSNotification *)notif {
[self setViewMoveUp:NO];
}
- (void)keyboardWillShow:(NSNotification *)notif{
[self setViewMoveUp:YES];
}
- (void)textFieldDidBeginEditing:(UITextField *)textField {
stayup = YES;
[self setViewMoveUp:YES];
}
- (void)textFieldDidEndEditing:(UITextField *)textField {
stayup = NO;
[self setViewMoveUp:NO];
}
//method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMoveUp:(BOOL)moveUp
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.3]; // if you want to slide up the view
[UIView setAnimationBeginsFromCurrentState:YES];
CGRect rect = self.view.frame;
if (moveUp)
{
// 1. move the view's origin up so that the text field that will be hidden come above the keyboard
// 2. increase the size of the view so that the area behind the keyboard is covered up.
if (rect.origin.y == 0 ) {
rect.origin.y -= kOFFSET_FOR_KEYBOARD;
//rect.size.height += kOFFSET_FOR_KEYBOARD;
}
}
else
{
if (stayup == NO) {
rect.origin.y += kOFFSET_FOR_KEYBOARD;
//rect.size.height -= kOFFSET_FOR_KEYBOARD;
}
}
self.view.frame = rect;
[UIView commitAnimations];
}
Try this methods. Edit it according to your requirement.