iOS -键盘显示与隐藏

目前我所接触到的键盘处理方法有两种，第一种是通过约束，第二种是通过transform。

// 监听键盘通知
-（void)viewDidLoad{
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}

<pre name="code" class="objc"> - (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}

#pragma mark - 键盘处理
- (void)keyboardWillShow:(NSNotification *)note {
// 取出键盘最终的frame
CGRect rect = [note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
// 取出键盘弹出需要花费的时间
double duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
// 修改约束
self.bottomSpacing.constant = rect.size.height;
[UIView animateWithDuration:duration animations:^{
[self.view layoutIfNeeded];
}];
}

- (void)keyboardWillHide:(NSNotification *)note {
// 取出键盘弹出需要花费的时间
double duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
// 修改约束
self.bottomSpacing.constant = 0;
[UIView animateWithDuration:duration animations:^{
[self.view layoutIfNeeded];
}];
}

上面是第一种方法，简单来说就是通过底部约束来达到这样一个效果。

// 监听键盘通知
-（void)viewDidLoad{

// 监听键盘通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];
}

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

#pragma mark - 键盘处理
- (void)keyboardWillChangeFrame:(NSNotification *)note {
// 取出键盘最终的frame
CGRect rect = [note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
// 取出键盘弹出需要花费的时间
double duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
// 修改transform
[UIView animateWithDuration:duration animations:^{
CGFloat ty = [UIScreen mainScreen].bounds.size.height - rect.origin.y;
self.view.transform = CGAffineTransformMakeTranslation(0, - ty);
}];
}

第二种方法就是通过transform将整个屏幕的view向上移动或向下移动一个键盘的高度。

（如果有新方法欢迎回帖