网格中的交互控件

Question

我一直在设计一个网页上有一个网格的网站。网格中有多个comboBoxes。这些组合框进行交互。例如，当一个值被用户更改时，另一个值被更改或被禁用/启用等。

我发现为了做到这一点，我不得不经常使用FindControl。就像在一个组合框的selectedindexchanged事件中一样，我需要找到另一个comboBox。

这似乎是一种相当混乱的做事方式。它似乎也让系统暴露在编译器找不到的错误中，比如如果一个组合框的id后来被更改了。

谁能告诉我有没有更好的方法？

Answer 1

我有一个web应用程序，它也广泛使用各种FindControl排列，以实现您所描述的。尽管它很脆弱(未经测试就不要更改控件is )，但可以通过一些实用函数使其稍微变得不那么麻烦。下面是我使用的所有FindControl类型的函数--这至少可能对您有所帮助。

/// <summary>
/// Recursively searches for a control within the heirarchy of a given control.
/// </summary>
/// <param name="root">The control to search within.</param>
/// <param name="id">The ID of the control to find.</param>
/// <returns>The Control object of the found control, or null if the control isn't found.</returns>
public static Control FindControlRecursive(Control root, string id)
{
    if (root.ID == id) return root;

    foreach (Control c in root.Controls)
    {
        Control t = FindControlRecursive(c, id);
        if (t != null) return t;
    }

    return null;
}

/// <summary>
/// Recursively searches for a control within the heirarchy of a given control using the Client ID
/// of the control. Calling this too early in the lifecycle may not behave as expected.
/// </summary>
/// <param name="root">The control to search within.</param>
/// <param name="clientID">The Client ID of the control to find.</param>
/// <returns>The Control object of the found control, or null if the control isn't found.</returns>
public static Control FindControlRecursiveByClientID(Control root, string clientID)
{
 if (0 == String.Compare(root.ClientID, clientID, true)) return root;

 foreach (Control c in root.Controls)
 {
  Control t = FindControlRecursiveByClientID(c, clientID);
  if (t != null) return t;
 }

 return null;
}

/// <summary>
/// Recursively searches for a group of controls within the heirarchy of a given control tree using the ID
/// of the control.
/// </summary>
/// <param name="root">The control tree to search within.</param>
/// <param name="id">The ID of the control to find.</param>
/// <returns>
/// A collection of the found controls. The collection will be empty if none are found.
/// </returns>
public static List<Control> FindControlsRecursive(Control root, string id)
{
 List<Control> collection = new List<Control>();
 FindControlRecursive(root, id, collection);
 return collection;
}

private static void FindControlRecursive(Control root, string id, List<Control> collection)
{
 foreach (Control c in root.Controls)
 {
  if (0 == String.Compare(c.ID, id, true)) collection.Add(c);
  else FindControlRecursive(c, id, collection);
 }
}

/// <summary>
/// Recursively searches for a control within the heirarchy of a given control using the type
/// of the control.
/// </summary>
/// <typeparam name="T">The type of the control to find.</typeparam>
/// <param name="root">The control to search within.</param>
/// <returns>
/// The Control object of the found control, or null if the control isn't found.
/// </returns>
public static T FindControlRecursiveByType<T>(Control root)
 where T : Control
{
 if (root is T) return (T)root;
 foreach (Control c in root.Controls)
 {
  Control t = FindControlRecursiveByType<T>(c);
  if (t != null) return (T)t;
 }
 return null;
}

/// <summary>
/// Recursively searches for a set of controls within the heirarchy of a given control using the type
/// of the control.
/// </summary>
/// <typeparam name="T">The type of the control to find.</typeparam>
/// <param name="root">The control to search within.</param>
/// <returns>
/// A generic List object containing the controls found, or an empty List of none were found.
/// </returns>
public static List<T> FindControlsRecursiveByType<T>(Control root)
 where T : Control
{
 List<T> collection = new List<T>();
 FindControlRecursiveByType<T>(root, collection);
 return collection;
}

private static void FindControlRecursiveByType<T>(Control root, List<T> collection)
 where T : Control
{
 foreach (Control c in root.Controls)
 {
  if (c is T) collection.Add((T)c);
  else FindControlRecursiveByType<T>(c, collection);
 }
}

Answer 2

正是由于这个原因，我从ASP.NET转向使用Silverlight进行开发，并利用了它的MVVM模式。即使使用ASP.Net的GridView项模板，每一项也不能直接绑定到同一模板中的另一项，也不能感知或引用另一项。您的后台代码必须在某种程度上(通常是最完整的)知道视图控件的组成层次结构。

下面是你可以做些什么来更接近“更好的绑定世界”。您仍然可以将您的组合框绑定到相同的列表数据源，但是当创建每一行项目/控件时，您需要将每个项目与一个对象(即标记项目)相关联。然后，在控件的事件处理中，您将检索与引发事件的控件关联的标记项关联的其他控件，并对它们执行您希望执行的操作。

我知道，这不是个好主意，但我想都没想过。也许当我有时间对此进行更多的思考时，我可以更新这篇文章。

Answer 3

使用事件来做通知怎么样？