IOS鍵盤彈出、隱藏

IOS鍵盤

• UIKeyboardFrameBeginUserInfoKey：動畫開始前鍵盤的size
• UIKeyboardFrameEndUserInfoKey：動畫結束後鍵盤的size

- (void)registeKeyboardNotification
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];
    
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}

- (void)unRegisteKeyboardNotification
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    // 動畫結束後鍵盤的size
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
       
    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;
    
    // frame爲scrollView要滑動到的位置
    CGRect frame;
    [scrollView scrollRectToVisible:frame animated:YES];
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;

    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;
}