ios - 为所有 View Controller 编写一个通用方法，以在出现键盘时调整内容 View (UIScrollView)的框架

Question

在我的 iOS 应用程序中，几乎有 10 个 ViewController，其中存在 UITextFields。我实现了在键盘出现时向上移动内容 View 的功能。

https://developer.apple.com/library/content/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

这个网站解释了一切。

但我的问题是我必须在每个 View Controller 中重复相同的代码。他们有什么办法让我可以编写适用于我所有 10 个 ViewController 的通用类或方法，从而实现代码的可重用性？

从苹果文档中，我必须使用以下方法。但是我被困在一个地方，我必须将 ScrollView 和事件文本字段的实例(对于每个 View Controller ，这些实例都是不同的)传递给我的通用类/方法。

// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
    [[NSNotificationCenter defaultCenter] addObserver:self
            selector:@selector(keyboardWasShown:)
            name:UIKeyboardDidShowNotification object:nil];
 
   [[NSNotificationCenter defaultCenter] addObserver:self
             selector:@selector(keyboardWillBeHidden:)
             name:UIKeyboardWillHideNotification object:nil];
 
}
 
// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
 
    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;
 
    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your app might not need or want this behavior.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
        [self.scrollView scrollRectToVisible:activeField.frame animated:YES];
    }
}
 
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    scrollView.contentInset = contentInsets;
    scrollView.scrollIndicatorInsets = contentInsets;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    activeField = textField;
}
 
- (void)textFieldDidEndEditing:(UITextField *)textField
{
    activeField = nil;
}

Answer 1

在基本 View Controller 中为 scrollView 创建属性，并在每个派生 View Controller 的 viewDidLoad 方法中初始化它。同时将 activeField 属性移动到基本 View Controller 。