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關於鍵盤出現與隱藏時調整UITextField的顯示位置問題
1、首先在ViewDidLoad裏麵添加注冊鍵盤隱藏與出現的通知：
///< 注冊通知，以便在鍵盤將要出現時，調整頁麵
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(onKeyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
///< 注冊通知，以便在鍵盤將要隱藏時，恢複頁麵
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(onKeyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
2、在viewWillDisappear裏移除對鍵盤隱藏與出現的通知：
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
/// 注意：在此處需要移除通知，否則容易照成崩潰
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
return;
}
3、實現鍵盤出現、隱藏時的通知回調：
#pragma mark - UIKeyboardWillShowNotification 通知
- (void)onKeyboardWillShow:(NSNotification *)notification {
CGRect frame = self.view.frame;
if (frame.origin.y < 0) {
return;
}
// 獲取鍵盤的高度
CGFloat keyboardHeight = [self keyboardHeightWithKeyboardNotification:notification];
frame.origin.y -= (keyboardHeight - 20);
[UIView animateWithDuration:0.35 animations:^{
self.view.frame = frame;
}];
return;
}
#pragma mark - UIKeyboardWillHideNotification 通知
- (void)onKeyboardWillHide:(NSNotification *)notification {
CGRect frame = self.view.frame;
if (frame.origin.y > 0) {
return;
}
// 獲取鍵盤的高度
CGFloat keyboardHeight = [self keyboardHeightWithKeyboardNotification:notification];
frame.origin.y += (keyboardHeight - 20);
[UIView animateWithDuration:0.35 animations:^{
self.view.frame = frame;
}];
return;
}
/// 獲取鍵盤高度
- (CGFloat)keyboardHeightWithKeyboardNotification:(NSNotification *)notification {
NSDictionary *info = notification.userInfo;
NSValue *value = [info objectForKey:UIKeyboardFrameBeginUserInfoKey];
CGSize keyboardSize = [value CGRectValue].size;
CGFloat keyboardHeight = keyboardSize.height;
return keyboardHeight;
}
最後更新：2017-04-03 08:26:18