UITextField控件处理键盘弹出时遮住输入框的问题

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。

- (void)keyboardWillShow:(NSNotification *)noti
{
//键盘输入的界面调整
//键盘的高度
float height = 216.0;
CGRect frame = self.view.frame;
frame.size = CGSizeMake(frame.size.width, frame.size.height - height);
[UIView beginAnimations:@"Curl"context:nil];//动画开始
[UIView setAnimationDuration:0.30];
[UIView setAnimationDelegate:self];
[self.view setFrame:frame];
[UIView commitAnimations];
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
// When the user presses return, take focus away from the text field so that the keyboard is dismissed.
NSTimeInterval animationDuration = 0.30f;
[UIView beginAnimations:@"ResizeForKeyboard" context:nil];
[UIView setAnimationDuration:animationDuration];
CGRect rect = CGRectMake(0.0f, 0.0f, self.view.frame.size.width, self.view.frame.size.height);
self.view.frame = rect;
[UIView commitAnimations];
[textField resignFirstResponder];
return YES;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
CGRect frame = textField.frame;
int offset = frame.origin.y + 32 - (self.view.frame.size.height - 216.0);//键盘高度216
NSTimeInterval animationDuration = 0.30f;
[UIView beginAnimations:@"ResizeForKeyBoard" context:nil];
[UIView setAnimationDuration:animationDuration];
float width = self.view.frame.size.width;
float height = self.view.frame.size.height;
if(offset > 0)
{
CGRect rect = CGRectMake(0.0f, -offset,width,height);
self.view.frame = rect;
}
[UIView commitAnimations];
}