My solution has 4 step:
- Step 1: the function listens when the keyboard appears
- (void)keyboardWasShown:(NSNotification *)notification {
// Get the size of the keyboard.
CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
//top: 64 for navigation bar, 0 for without navigation
UIEdgeInsets contentInsets = UIEdgeInsetsMake(64, 0, keyboardSize.height, 0);
_scrollView.contentInset = contentInsets;
_scrollView.scrollIndicatorInsets = contentInsets;
}
- Step 2: the function listens when the keyboard disappears
- (void)keyboardWillHide:(NSNotification *)notification {
//top: 64 for navigatiob bar
UIEdgeInsets contentInsets = UIEdgeInsetsMake(64, 0, 0, 0);
[_editScrollView setContentInset: contentInsets];
[_editScrollView setScrollIndicatorInsets: contentInsets];
}
- Step 3: add these functions to the notification center:
- (void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasShown:) name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}
- Step 4: remove listen when view controller disappers
- (void)viewDidDisappear:(BOOL)animated{
[super viewDidDisappear:animated];
[[NSNotificationCenter defaultCenter]removeObserver:self name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter]removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}