resize UIView when showing the keyboard for iphone

问题:

This question already has an answer here:

• How to resize UITextView on iOS when a keyboard appears? 10 answers

I will show you an example with the well known whatsapp When you touch inside the text the keyboard pops up , so I have to move or shift all that bar up and resize the view to half, so I can still see the text that I'm typing and the send button

Phase 1: http://www.appbank.net/wp-content/uploads/2010/10/WhatsAppMessenger-18.jpg

Phase 2: http://www.onetooneglobal.com/wp-content/uploads/2011/02/onetoone_whatsapp_2.png

What would be the best way to achieve this?

回答1:

#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.

回答2:

You'll want to listen to the UIKeyboardDidShowNotification and UIKeyboardDidHideNotification, and in the method that corresponds to the selector you've provided the notification center resize your views at will (typically by changing the UIView.frame property)