problem while moving the screen upwards when we hit on the text field

i have used following code to move the screen upwards when we hit on text field ,,this code was working fine with xcode 3 but its not working with xcode 4 ,,its not giving any error but when we touch on the text field screen ill go upwards to a greater height ,,some times wont come back ti original position

- (void)keyboardWasShown:(NSNotification *)aNotification {
    if ( keyboardShown )
        return;

    if ((activeField==tfText[4])||(activeField==tfText[5]))
    {


#if __IPHONE_OS_VERSION_MIN_REQUIRED <= __IPHONE_3_2
        CGRect _keyboardEndFrame;

        [[aNotification.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue:&_keyboardEndFrame];
        CGFloat keyboardSize;
        if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait || [[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown) 
        {
            keyboardSize = _keyboardEndFrame.size.height;
        }
        else {
            keyboardSize = _keyboardEndFrame.size.width;
        }

        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y -= keyboardSize-70;
        frame.size.height += keyboardSize-70;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];
#else
        NSDictionary *info = [aNotification userInfo];
        NSValue *a开发者_运维知识库Value = [info objectForKey:UIKeyboardBoundsUserInfoKey];
        CGSize keyboardSize = [aValue CGRectValue].size;

        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y -= keyboardSize.height-70;
        frame.size.height += keyboardSize.height-70;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];





#endif

        viewMoved = YES;
    }

    keyboardShown = YES;
}


- (void)keyboardWasHidden:(NSNotification *)aNotification {
    if ( viewMoved ) {

#if __IPHONE_OS_VERSION_MIN_REQUIRED <= __IPHONE_3_2
        CGRect _keyboardEndFrame;
        [[aNotification.userInfo valueForKey:UIKeyboardBoundsUserInfoKey] getValue:&_keyboardEndFrame];
        CGFloat keyboardSize;
        if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait || [[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown) {
            keyboardSize = _keyboardEndFrame.size.height;
        }
        else {
            keyboardSize = _keyboardEndFrame.size.width;
        }

        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y += keyboardSize-70;
        frame.size.height -= keyboardSize-70;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];
#else
        NSValue *aValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];
        CGSize keyboardSize = [aValue CGRectValue].size;

        NSTimeInterval animationDuration = 0.300000011920929;
        CGRect frame = self.view.frame;
        frame.origin.y += keyboardSize.height-70;
        frame.size.height -= keyboardSize.height-70;
        [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
        [UIView setAnimationDuration:animationDuration];
        self.view.frame = frame;
        [UIView commitAnimations];



#endif

        viewMoved = NO;
    }

    keyboardShown = NO;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField 
{
    activeField = textField;
}


- (void)textFieldDidEndEditing:(UITextField *)textField 
{
    activeField = nil;
    // Additional Code
}

using following code i am calling the above methods

- (void)viewDidLoad 
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasHidden:)
                                                 name:UIKeyboardDidHideNotification
                                               object:nil];
}

- (void)viewDidLoad 
{
    [super viewDidLoad];

// register for keyboard notifications
[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(keyboardWillShow:) 
                                             name:UIKeyboardWillShowNotification 
                                           object:self.view.window];
// register for keyboard notifications
[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(keyboardWillHide:) 
                                             name:UIKeyboardWillHideNotification 
                                           object:self.view.window];
    keyboardIsShown = NO;
        //make contentSize bigger than your scrollSize (you will need to figure out for your own use case)
    CGSize scrollContentSize = CGSizeMake(320, 345);
    self.scrollView.contentSize = scrollContentSize;
    }


- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;

    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self 
                                                    name:UIKeyboardWillShowNotification 
                                                  object:nil]; 
    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self 
                                                    name:UIKeyboardWillHideNotification 
                                                  object:nil];  

}

- (void)keyboardWillHide:(NSNotification *)n
{
    NSDictionary* userInfo = [n userInfo];

    // get the size of the keyboard
    NSValue* boundsValue = [userInfo objectForKey:UIKeyboardBoundsUserInfoKey];
    CGSize keyboardSize = [boundsValue CGRectValue].size;


    // resize the scrollview
    CGRect viewFrame = self.scrollView.frame;
    // I'm also subtracting a constant kTabBarHeight because my UIScrollView was offset by the UITabBar so really only the portion of the keyboard that is leftover pass the UITabBar is obscuring my UIScrollView.
    viewFrame.size.height += (keyboardSize.height - kTabBarHeight);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    // The kKeyboardAnimationDuration I am using is 0.3
    [UIView setAnimationDuration:kKeyboardAnimationDuration];
    [self.scrollView setFrame:viewFrame];
    [UIView commitAnimations];

    keyboardIsShown = NO;
}

- (void)keyboardWillShow:(NSNotification *)n
{
    // This is an ivar I'm using to ensure that we do not do the frame size adjustment on the UIScrollView if the keyboard is already shown.  This can happen if the user, after fixing editing a UITextField, scrolls the resized UIScrollView to another UITextField and attempts to edit the next UITextField.  If we were to resize the UIScrollView again, it would be disastrous.  NOTE: The keyboard notification will fire even when the keyboard is already shown.
    if (keyboardIsShown) {
        return;
    }

    NSDictionary* userInfo = [n userInfo];

    // get the size of the keyboard
    NSValue* boundsValue = [userInfo objectForKey:UIKeyboardBoundsUserInfoKey];
    CGSize keyboardSize = [boundsValue CGRectValue].size;

    // resize the noteView
    CGRect viewFrame = self.scrollView.frame;
    // I'm also subtracting a constant kTabBarHeight because my UIScrollView was offset by the UITabBar so really only the portion of the keyboard that is leftover pass the UITabBar is obscuring my UIScrollView.
    viewFrame.size.height -= (keyboardSize.height - kTabBarHeight);

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    // The kKeyboardAnimationDuration I am using is 0.3
    [UIView setAnimationDuration:kKeyboardAnimationDuration];
    [self.scrollView setFrame:viewFrame];
    [UIView commitAnimations];

    keyboardIsShown = YES;
}