出现键盘时的滚动视图：库还是DIY？

Question

I've had it up to my neck trying to make the whole view moving to the appropriate UITextField when a user taps on a respective object look seamless. I know that I'm not the only one that absolutely hates doing this too.

What is the best approach to making this work as beautifully as possible with the least amount of work possible?

I've tried out TPKeyboardAvoiding , and it totally sucked.

Right now, I've got this code going, but it sucks as well in it's own special way:

- (void)viewDidLoad
{
    self.view.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin);
    self.scrollView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin);

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}


- (void)keyboardWasShown:(NSNotification *)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;

    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your application might not need or want this behavior.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, self.activeField.frame.origin) ) {
        CGPoint scrollPoint = CGPointMake(0.0, self.activeField.frame.origin.y-kbSize.height);
        [self.scrollView setContentOffset:scrollPoint animated:YES];
    }
}

- (void)keyboardWillBeHidden:(NSNotification *)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    self.scrollView.contentInset = contentInsets;
    self.scrollView.scrollIndicatorInsets = contentInsets;
}

Answer 1

For me, it works TPKeyboardAvoiding , I use it in all my projects. Have you tried to:

1. Add a UIScrollView into your view controller's xib
2. Set the scroll view's class to TPKeyboardAvoidingScrollView (still in the xib, via the identity inspector)
3. Place all your controls within that scrollview ?

I also find this solution : Keyboard Manager

1. Download demo project
2. Just drag and drop KeyboardManager and SegmenedNextPrevious classes to your project

3. In your appDelegate write only one line of code:

   [KeyBoardManager installKeyboardManager];

Good luck!

Answer 2

Did you know that if your view controller derives from UITableViewController, scrolling the table view is automatic when the keyboard displays when a text field or text view gets focus? You don't have to do anything. That being said, it may not work well for your app to refactor the UI so that it uses a table view with static cells instead of whatever you're doing now, though.

If this wont work for you, you can change your scroll view's contenSize to be the size of your visible area when the keyboard is shown and then call scrollRectToVisible:animated: on your scroll view passing it the rect of your textfield inside of your keyboardWasShown: selector.