iOS 输入时键盘处理问题

在iOS的开发过程中，有时候需要处理键盘的弹出和收回。

以及键盘弹出收回时、view的处理

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）

//监听键盘的通知
[[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：

- (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];

self.reportTableView.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];

self.reportTableView.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,[UIScreen mainScreen].bounds.size.height  - 55 - 64);

[UIView commitAnimations];
}

step 3:
在退出视图的时候注销通知
viewDidUnload:

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

step 4:
dealloc:

-(void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self name:nil object:nil];
}

这些代码是摘自apple sample code KeyboardAccessory.

细节自己修改下就好了，比如那个reportTableView、CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,[UIScreen mainScreen].bounds.size.height - 55 - 64)