UITextField控件处理键盘弹出时遮住输入框的问题

原文连接： 
http://www.devdiv.com/thread-70159-1-1.html 

实现以下三个方法，如果弹出的键盘会遮住输入框
，整体的界面会向上移动，这样就不会遮住输入框了。自己增加UITextFieldDelegate委托。 
只适合iPhone,如果想要支持iPad,只要把216改成iPad上面键盘的高度即可。

 1 - (void)keyboardWillShow:(NSNotification *)noti

 2 {

 3         //键盘输入的界面调整

 4         //键盘的高度

 5         float height = 216.0;

 6         CGRect frame = self.view.frame;

 7         frame.size = CGSizeMake(frame.size.width, frame.size.height - height);

 8         [UIView beginAnimations:@"Curl"context:nil];//动画开始

 9         [UIView setAnimationDuration:0.30];

10         [UIView setAnimationDelegate:self];

11         [self.view setFrame:frame];

12         [UIView commitAnimations];

13 }

14

15

16 - (BOOL)textFieldShouldReturn:(UITextField *)textField

17 {

18     // When the user presses return, take focus away from the text field so that the keyboard is dismissed.

19     NSTimeInterval animationDuration = 0.30f;

20     [UIView beginAnimations:@"ResizeForKeyboard" context:nil];

21     [UIView setAnimationDuration:animationDuration];

22     CGRect rect = CGRectMake(0.0f, 0.0f, self.view.frame.size.width, self.view.frame.size.height);

23     self.view.frame = rect;

24     [UIView commitAnimations];

25     [textField resignFirstResponder];

26     return YES;

27 }

28

29 - (void)textFieldDidBeginEditing:(UITextField *)textField

30 {

31         CGRect frame = textField.frame;

32         int offset = frame.origin.y + 32 - (self.view.frame.size.height - 216.0);//键盘高度216

33         NSTimeInterval animationDuration = 0.30f;

34         [UIView beginAnimations:@"ResizeForKeyBoard" context:nil];

35         [UIView setAnimationDuration:animationDuration];

36         float width = self.view.frame.size.width;

37         float height = self.view.frame.size.height;

38         if(offset > 0)

39         {

40                 CGRect rect = CGRectMake(0.0f, -offset,width,height);

41                 self.view.frame = rect;

42         }

43         [UIView commitAnimations];

44 }

另外我自己做了一点修改： 
在实际用的时候，键盘消失原来的控件并没有回归都原来的位置，而是上移了20个像素，我估计是因为顶部Bar的原因，只要将22行代码改成如下就可以了： 
CGRect
rect = CGRectMake(0.0f, 20.0f, self.view.frame.size.width,
self.view.frame.size.height);