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）

 

1. // Observe keyboard hide and show notifications to resize the text view appropriately.
2.     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
3.     [[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：

 

1. - (void)keyboardWillShow:(NSNotification *)notification {
2.    
3.     /*
4.      Reduce the size of the text view so that it's not obscured by the keyboard.
5.      Animate the resize so that it's in sync with the appearance of the keyboard.
6.      */
8.     NSDictionary *userInfo = [notification userInfo];
9.    
10.     // Get the origin of the keyboard when it's displayed.
11.     NSValue* aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
13.     // 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.
14.     CGRect keyboardRect = [aValue CGRectValue];
15.     keyboardRect = [self.view convertRect:keyboardRect fromView:nil];
16.    
17.     CGFloat keyboardTop = keyboardRect.origin.y;
18.     CGRect newTextViewFrame = self.view.bounds;
19.     newTextViewFrame.size.height = keyboardTop - self.view.bounds.origin.y;
20.    
21.     // Get the duration of the animation.
22.     NSValue *animationDurationValue = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
23.     NSTimeInterval animationDuration;
24.     [animationDurationValue getValue:&animationDuration];
25.    
26.     // Animate the resize of the text view's frame in sync with the keyboard's appearance.
27.     [UIView beginAnimations:nil context:NULL];
28.     [UIView setAnimationDuration:animationDuration];
29.    
30.     textView.frame = newTextViewFrame;
32.     [UIView commitAnimations];
33. }
36. - (void)keyboardWillHide:(NSNotification *)notification {
37.    
38.     NSDictionary* userInfo = [notification userInfo];
39.    
40.     /*
41.      Restore the size of the text view (fill self's view).
42.      Animate the resize so that it's in sync with the disappearance of the keyboard.
43.      */
44.     NSValue *animationDurationValue = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
45.     NSTimeInterval animationDuration;
46.     [animationDurationValue getValue:&animationDuration];
47.    
48.     [UIView beginAnimations:nil context:NULL];
49.     [UIView setAnimationDuration:animationDuration];
50.    
51.     textView.frame = self.view.bounds;
52.    
53.     [UIView commitAnimations];
54. }

step 3:

在退出视图的时候注销通知

viewDidUnload:

 

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

dealloc:

 

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