Question

在第一次尝试中，我试图通过向 int 或字符串注入 DialogBoxFactory 来保留变量的引用 IDialogFooterText ，并在我的工厂中调用'GetFooterDisplay（）'，然后返回一个字符串。我正在模拟对话框页面增量，并应该接收更新的页面索引。

这不能正常工作（然后我找到Eric Lippert的论坛答案，概述了我无法将ref参数存储在外部类'方法中并尝试其他路径的原因。

我的第二次尝试确实有效，但它似乎更脏，因为在 DialogFooterPagenum 我明确知道 DialogBoxFactory 的工厂类型。有什么其他方法可以获得页面索引而无需直接引用工厂实例化 IDIalogFooterText ？

    public class DialogBoxFactory 
    {

    public int _currentPageIndex = 0;

    private string[] _dialogText = new string[10]; //filled with dialog content

    //an example I've left to demonstrate the need for injecting different parameter types in their constructors
    //private IDialogFooterText = new DialogFooterText( "ok" );

    private IDialogFooterText  _footerText = new DialogFooterPagenum( ref _currentPageIndex, dialogText.Length );


    void Start(){

        _currentPageIndex +=1;

        Debug.Log( _footerText.GetFooterDisplay() );
        //expecting the log to show "1/10"

    }


}

public class DialogFooterPagenum : IDialogFooterText 
{

private int _pageIndex;
private int _dialogLength;

public DialogFooterPagenum( ref int p_pageIndex, int p_dialogLength ){

    _pageIndex = p_pageIndex;
    _dialogLength = p_dialogLength;

}

public string GetFooterDisplay(){

    return _pageIndex.ToString() + " /  " + _dialogLength;

}

}

第二次尝试版本 - 自参考无法正常工作后重做

public class DialogBoxFactory 
{

public int _currentPageIndex = 0;

private string[] _dialogText = new string[10]; //filled with dialog content

//an example I've left to demonstrate the need for injecting different parameter types in their constructors
//private IDialogFooterText = new DialogFooterText( "ok" );

private IDialogFooterText  _footerText = new DialogFooterPagenum( this, dialogText.Length );


void Start(){

    _currentPageIndex +=1;

    Debug.Log( _footerText.GetFooterDisplay() );
    //expecting the log to show "1/10"

}


}


 public class DialogFooterPagenum : IDialogFooterText 
 {

private int _dialogLength;
private DialogBoxFactory _factory;

//this works now but is unacceptable since I wish this class to be unaware of the factory instantiating this class.

public DialogFooterPagenum( DialogBoxFactory p_factory , int p_dialogLength ){

    _factory = p_factory;
    _dialogLength = p_dialogLength;

}

public string GetFooterDisplay(){

    return _factory._currentPageIndex.ToString() + " /  " + _dialogLength;

}

}

Answer 1

我看不出有任何理由不在IDialogFooterText实施中存储当前页面索引：

interface IDialogFooterText
{
    string GetFooterDisplay();
    int CurrentPageIndex { get; set; }
}

public class DialogBoxFactory
{
    IDialogFooterText _footerText = // ...

    void Start()
    {
        _footerText.CurrentPageIndex += 1;

        Debug.Log( _footerText.GetFooterDisplay() );
    }
}

Answer 2

我还没有深入阅读你的问题。我只能看到您需要引用可变page index到DialogFooterPagenum。 PageIndex班可以解决问题吗？

class PageIndex{
    private int index;
    public int Index{get{return index;} 
        set{
            index = value;
            OnPageIndexChange();
        }
    }

    public Action OnPageIndexChange{get;set;} // change this to event-based
}

这样您就可以保留对页面索引的引用。

有没有更好的方法在单个类接口中保存工厂的变量引用？

2 个答案: