Question

大家早上好/晚上好。我试图这样做，当键盘出现时，文本字段和整个视图向上移动。我正在使用一些NSNotificationCenter代码来查找屏幕上的键盘（UIKeyboardDidShowNotification）。

调用此方法没有问题，然后它正确地更改视图。但是第一次和第一次调用它时，视图将重置为默认值，而不是新值。

然后，第二次，第三次等等，它完美无缺。我怎样才能解决这个问题？

ViewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardOnScreen:) name:UIKeyboardDidShowNotification object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardOffScreen:) name:UIKeyboardDidHideNotification object:nil];

方法：

-(void)keyboardOnScreen:(NSNotification *)notification
{



    NSDictionary *info  = notification.userInfo;
    NSValue      *value = info[UIKeyboardFrameEndUserInfoKey];

    CGRect rawFrame      = [value CGRectValue];
    CGRect keyboardFrame = [self.view convertRect:rawFrame fromView:nil];

    double y = keyboardFrame.size.height;


    if (y == 0) {

        NSLog(@"prevented error!");


    } else {

    NSLog(@"%f", y);


    CGRect frame = [input frame];



    double nonorigil = origianltexty - y;
    frame.origin.x = originaltextx;
    frame.origin.y = nonorigil;


    [input setFrame:frame];



    CGRect fra = [scrollView frame];


    CGRect screenBound = [[UIScreen mainScreen] bounds];
    CGSize screenSize = screenBound.size;
    CGFloat screenWidth = screenSize.width;
    CGFloat screenHeight = screenSize.height;

    fra.size.height = (screenHeight - y) - 60;



    [scrollView setFrame:fra];

    CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
    [scrollView setContentOffset:bottomOffset animated:NO];

    }


}

-(void) keyboardOffScreen: (NSNotification *)notification {

    NSLog(@"keyboard went away");

}

当＆＃34;发送＆＃34;按下按钮......

- (BOOL)textFieldShouldReturn:(UITextField *)textField {

   input.text = @"";

    CGRect frame = [input frame];

    frame.origin.x = originaltextx;
    frame.origin.y = origianltexty;

    [input setFrame:frame];

    [textField resignFirstResponder];
    return NO;
}

Answer 1

我最终通过使用自动布局和更改约束来克服这一点，而不是通知委托函数中的帧大小或位置，如下所示：

P.S。我没有使用scrollview只是简单的移动视图，但它应该工作类似

func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if !keyboardIsShown{
            self.infoViewTopConstraint.constant -= keyboardSize.height
            self.infoViewBottomConstraint.constant += keyboardSize.height
            self.view.setNeedsLayout()
            self.view.layoutIfNeeded()
            keyboardIsShown = true
        }
    }
}

func keyboardWillHide(notification: NSNotification) {
    if keyboardIsShown {
        self.infoViewTopConstraint.constant += keyboardSize.height
        self.infoViewBottomConstraint.constant -= keyboardSize.height
        self.view.setNeedsLayout()
        self.view.layoutIfNeeded()
        keyboardIsShown = false
    }
}

首次启动键盘时查看重置为默认值（Xcode）

1 个答案: