iOS:键盘弹出和收起的通知使用

介绍：不论是UITextField，还是UITextView，使用它们输入文字时都是有键盘的弹出，此时可能会挡住我们创建的一分部其他视图,此时，就需要根据键盘的高度将我们被隐藏的部分View做向上或者向下平移，使用tansform或者动画UIViewAnimation均可，使用如下：

这是跟键盘有关的所有通知：

//键盘显示和隐藏
UIKIT_EXTERN NSString *const UIKeyboardWillShowNotification;
UIKIT_EXTERN NSString *const UIKeyboardDidShowNotification;
UIKIT_EXTERN NSString *const UIKeyboardWillHideNotification;
UIKIT_EXTERN NSString *const UIKeyboardDidHideNotification;

//键盘弹出后，通过这个key可以取出需要的键盘的frame,我们就是通过这frame的高度来做平移的
UIKIT_EXTERN NSString *const UIKeyboardFrameBeginUserInfoKey        NS_AVAILABLE_IOS(3_2); // NSValue of CGRect
UIKIT_EXTERN NSString *const UIKeyboardFrameEndUserInfoKey          NS_AVAILABLE_IOS(3_2); // NSValue of CGRect
UIKIT_EXTERN NSString *const UIKeyboardAnimationDurationUserInfoKey NS_AVAILABLE_IOS(3_0); // NSNumber of double
UIKIT_EXTERN NSString *const UIKeyboardAnimationCurveUserInfoKey    NS_AVAILABLE_IOS(3_0); // NSNumber of NSUInteger (UIViewAnimationCurve)
UIKIT_EXTERN NSString *const UIKeyboardIsLocalUserInfoKey           NS_AVAILABLE_IOS(9_0); // NSNumber of BOOL

//键盘将要改变时的通知
UIKIT_EXTERN NSString *const UIKeyboardWillChangeFrameNotification  NS_AVAILABLE_IOS(5_0);
UIKIT_EXTERN NSString *const UIKeyboardDidChangeFrameNotification   NS_AVAILABLE_IOS(5_0);

// These keys are superseded by UIKeyboardFrameBeginUserInfoKey and UIKeyboardFrameEndUserInfoKey.
UIKIT_EXTERN NSString *const UIKeyboardCenterBeginUserInfoKey   NS_DEPRECATED_IOS(2_0, 3_2) __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardCenterEndUserInfoKey     NS_DEPRECATED_IOS(2_0, 3_2) __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardBoundsUserInfoKey        NS_DEPRECATED_IOS(2_0, 3_2) __TVOS_PROHIBITED;

demo：

//注册通知

    //首先在ViewDidload中添加对键盘通知的监听
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

//键盘将要显示

-(void)keyboardWillShow:(NSNotification *)notification
{
    //NSLog(@"keyboardWillShow:%@",notification);
    
    NSDictionary *userInfo = [notification userInfo];
    CGFloat duration = [[userInfo objectForKey:@"UIKeyboardAnimationDurationUserInfoKey"] doubleValue];
    CGRect rect = [[userInfo objectForKey:@"UIKeyboardFrameEndUserInfoKey"]CGRectValue];
    
    [UIView animateWithDuration:duration animations:^{
        self.view.transform = CGAffineTransformMakeTranslation(0, -(SCREEN_HEIGHT-rect.origin.y));
    }];
}

//键盘将要隐藏

-(void)keyboardWillHide:(NSNotification *)notification
{
    //NSLog(@"keyboardWillHide:%@",notification);
    
    NSDictionary *userInfo = [notification userInfo];
    CGFloat duration = [[userInfo objectForKey:@"UIKeyboardAnimationDurationUserInfoKey"] doubleValue];
    
    [UIView animateWithDuration:duration animations:^{
        self.view.transform = CGAffineTransformIdentity;
    }];
}