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如何解決 Keyboard 擋住 TextField 的問題呢？
- (void)viewDidLoad
{
[super viewDidLoad];
//指定 TextField 將使用其 delegate
self.nameField.delegate = self;
self.numberField.delegate = self;
//向 NotificationCenter 申請註冊，在 UIKeyboardDidShowNotification 時，
//會呼叫 keyboardDidShow (自訂的) 這個 selector。
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardDidShow:)
name:UIKeyboardDidShowNotification
object:nil];
//向 NotificationCenter 申請註冊，在 UIKeyboardWillHideNotification 時，
//會呼叫 keyboardWillHide (自訂的) 這個 selector。
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
}
-(void) keyboardDidShow: (NSNotification *) notification {
//取得鍵盤高度
NSValue * value = [[notification userInfo] valueForKey:UIKeyboardFrameBeginUserInfoKey];
CGFloat keyboardHeight = [value CGRectValue].size.height;
//以動畫的方式，將 View 的 Y軸 往上移一個鍵盤高
[UIView animateWithDuration:0.3f animations:^
{
CGRect frame = self.view.frame;
frame.origin.y -= keyboardHeight;
self.view.frame = frame;
}
];
}
-(void) keyboardWillHide: (NSNotification *) notification {
NSValue * value = [[notification userInfo] valueForKey:UIKeyboardFrameEndUserInfoKey];
CGFloat keyboardHeight = [value CGRectValue].size.height;
[UIView animateWithDuration:0.3f animations:^
{
CGRect frame = self.view.frame;
frame.origin.y += keyboardHeight;
self.view.frame = frame;
}
];
}
最後記得，註冊過的 Observer 要 release 掉
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
//只要有向 Notification Center 申請註冊，要記得 remove 掉
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
