iOS 根据键盘弹出调整view的高度
效果图:
gif.gif
其实实现键盘高度的弹出,让咱们的界面view始终在键盘的上面,实现非常简单.
首先要知道,苹果有一些监听键盘状态的各种key
UIKIT_EXTERN NSString *const UIKeyboardWillShowNotification __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardDidShowNotification __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardWillHideNotification __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardDidHideNotification __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardFrameBeginUserInfoKey NS_AVAILABLE_IOS(3_2) __TVOS_PROHIBITED; // NSValue of CGRect
UIKIT_EXTERN NSString *const UIKeyboardFrameEndUserInfoKey NS_AVAILABLE_IOS(3_2) __TVOS_PROHIBITED; // NSValue of CGRect
UIKIT_EXTERN NSString *const UIKeyboardAnimationDurationUserInfoKey NS_AVAILABLE_IOS(3_0) __TVOS_PROHIBITED; // NSNumber of double
UIKIT_EXTERN NSString *const UIKeyboardAnimationCurveUserInfoKey NS_AVAILABLE_IOS(3_0) __TVOS_PROHIBITED; // NSNumber of NSUInteger (UIViewAnimationCurve)
UIKIT_EXTERN NSString *const UIKeyboardIsLocalUserInfoKey NS_AVAILABLE_IOS(9_0) __TVOS_PROHIBITED; // NSNumber of BOOL
// Like the standard keyboard notifications above, these additional notifications include
// a nil object and begin/end frames of the keyboard in screen coordinates in the userInfo dictionary.
UIKIT_EXTERN NSString *const UIKeyboardWillChangeFrameNotification NS_AVAILABLE_IOS(5_0) __TVOS_PROHIBITED;
UIKIT_EXTERN NSString *const UIKeyboardDidChangeFrameNotification NS_AVAILABLE_IOS(5_0) __TVOS_PROHIBITED;
// These keys are superseded by UIKeyboardFrameBeginUserInfoKey and UIKeyboardFrameEndUserInfoKey.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;
这里我们用 UIKeyboardWillChangeFrameNotification来监听键盘frame的改变
1:添加通知的观察者
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyBoardFrameChange:) name:UIKeyboardWillChangeFrameNotification object:nil];
//当观察到键盘发生变化的通知后,就调用的方法
- (void)keyBoardFrameChange:(NSNotification *)userInfo{
// UIKeyboardAnimationCurveUserInfoKey = 7;
// UIKeyboardAnimationDurationUserInfoKey = "0.25";
// UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {375, 258}}";
// UIKeyboardCenterBeginUserInfoKey = "NSPoint: {187.5, 796}";
// UIKeyboardCenterEndUserInfoKey = "NSPoint: {187.5, 538}";
// UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 667}, {375, 258}}";
// UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 409}, {375, 258}}";
// UIKeyboardIsLocalUserInfoKey = 1;
// {
// UIKeyboardAnimationCurveUserInfoKey = 7;
// UIKeyboardAnimationDurationUserInfoKey = "0.25";
// UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {375, 258}}";
// UIKeyboardCenterBeginUserInfoKey = "NSPoint: {187.5, 538}";
// UIKeyboardCenterEndUserInfoKey = "NSPoint: {187.5, 796}";
// UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 409}, {375, 258}}";
// UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 667}, {375, 258}}";
// UIKeyboardIsLocalUserInfoKey = 1;
// }
// 1.修改试图的transform属性,让视图跟着键盘变化而变化
// ty = - 258 = 409 - view的高度;:表示键盘弹出的时候的值的变化
// ty = 0 意:transform是一种状态,当回到初始值状态为0,表示键盘回到原来的位置
// self.view.transform ==
// 1.1获取变化的值
NSDictionary *keyBoardDict = userInfo.userInfo;
CGRect endKeyBoardFrame = [keyBoardDict[UIKeyboardFrameEndUserInfoKey]CGRectValue];
//这里减去的是你需要调整的view的高度,如果view是全屏幕的可以用此方法
CGFloat ty = endKeyBoardFrame.origin.y - [UIScreen mainScreen].bounds.size.height;
// 1.2修改transform属性,让视图变化
// 1.3让修改有动画,获取动画的时间
CGFloat duration = [keyBoardDict[UIKeyboardAnimationDurationUserInfoKey]doubleValue];
[UIView animateWithDuration:duration animations:^{
self.view.transform = CGAffineTransformMakeTranslation(0, ty);
}];
}
也可以学以致用,调整tableView的某一个cell可以在输入时到键盘上面
