处理键盘弹出

最正规的办法，用通知
step 1：
在进入视图的时候添加监视：（viewDidLoad什么的）
复制代码

1. // Observe keyboard hide and show notifications to resize the text view appropriately.
       [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
       [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

step 2:
在键盘动作的时候移动视图：
复制代码

1. - (void)keyboardWillShow:(NSNotification *)notification {
      
       /*
        Reduce the size of the text view so that it's not obscured by the keyboard.
        Animate the resize so that it's in sync with the appearance of the keyboard.
        */
   
       NSDictionary *userInfo = [notification userInfo];
      
       // Get the origin of the keyboard when it's displayed.
       NSValue* aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
   
       // Get the top of the keyboard as the y coordinate of its origin in self's view's coordinate system. The bottom of the text view's frame should align with the top of the keyboard's final position.
       CGRect keyboardRect = [aValue CGRectValue];
       keyboardRect = [self.view convertRect:keyboardRect fromView:nil];
      
       CGFloat keyboardTop = keyboardRect.origin.y;
       CGRect newTextViewFrame = self.view.bounds;
       newTextViewFrame.size.height = keyboardTop - self.view.bounds.origin.y;
      
       // Get the duration of the animation.
       NSValue *animationDurationValue = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
       NSTimeInterval animationDuration;
       [animationDurationValue getValue:&animationDuration];
      
       // Animate the resize of the text view's frame in sync with the keyboard's appearance.
       [UIView beginAnimations:nil context:NULL];
       [UIView setAnimationDuration:animationDuration];
      
       textView.frame = newTextViewFrame;
   
       [UIView commitAnimations];
   }
   
   
   - (void)keyboardWillHide:(NSNotification *)notification {
      
       NSDictionary* userInfo = [notification userInfo];
      
       /*
        Restore the size of the text view (fill self's view).
        Animate the resize so that it's in sync with the disappearance of the keyboard.
        */
       NSValue *animationDurationValue = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
       NSTimeInterval animationDuration;
       [animationDurationValue getValue:&animationDuration];
      
       [UIView beginAnimations:nil context:NULL];
       [UIView setAnimationDuration:animationDuration];
      
       textView.frame = self.view.bounds;
      
       [UIView commitAnimations];
   }
   

step 3:
在退出视图的时候注销通知
viewDidUnload:
复制代码

1. [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
       [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];

dealloc:
复制代码

1. [[NSNotificationCenter defaultCenter] removeObserver:self name:nil object:nil];

这些代码是摘自apple sample code KeyboardAccessory.
些许细节自己修改下就好了，比如那个textView