asp.net +如何創建自定義多模板樹數據綁定控件？

Question

我不想使用asp.net的TreeView控件。 我想創建一個像多模板支持自定義模板數據綁定控件 -

<asp:MtNavigationControl> 

    <ItemTemplate> 
    ... 
    ... 
    </ItemTemplate> 

    <SelectedItemTemplate> 
    ... 
    ... 
    </SelectedItemTemplate> 

    <ParentItemTemplate> 
    ... 
    ... 
    </ParentSelectedItemTemplate> 

    <SelectedParentItemTemplate> 
    ... 
    ... 
    </SelectedParentSelectedItemTemplate> 

</asp:MtNavigationControl> 

我的數據是一樣 -

class Employee 
{ 
     string EmployeeName 
     List<Employee> Employees 
} 

有誰知道如何完成的呢？請幫忙 ！！！

Answer 1

該死的，我想我可能已經找到了我正在尋找的東西。我有同樣的問題，我有近乎完整的。我不確定這是我的班級（TreeBranches）還是下面的班級。似乎在初始渲染上效果很好。但是，每個回發似乎都會渲染兩次。我已經嘗試了像Controls.Clear（）這樣的東西，但.UniqueID似乎總是用於第二組控制。

基本上，我的TreeBranches只是分支對象的集合類。非常類似於您的員工示例。該模板只不過是以下內容：

<h2><a href='<%= this.NavigationUrl %>'><%= this.Title %></a></h2> 
<asp:PlaceHolder ID="phContents" runat="server" EnableViewState="true"></asp:PlaceHolder> 

它將生成UL下面有LI的。如果存在嵌套分支，那麼作爲父母的LI中將包含新的UL。這可以儘可能深。

using System; using System.Collections.Generic;使用System.Linq的 ; using System.Web.UI; using System.Web.UI.WebControls; using System.Text; using System.ComponentModel;使用System.Collections的 ;

命名空間Website.Controls { 公共部分類HeirarchicalList：System.Web.UI.UserControl {

private ITemplate _layoutTemplate = null; 
    private ITemplate _itemTemplate = null; 
    private string _LayoutPlaceholderID = ""; 

    #region Public Properties 

    public TreeBranches DataSource { get; set; } 

    /// <summary> 
    /// Gets or Sets the Header for this controls <h2> element. 
    /// </summary> 
    [PersistenceMode(PersistenceMode.Attribute)] 
    public string Title { get; set; } 

    /// <summary> 
    /// Gets or Sets the Class name for the outermost LayoutTemplate item. 
    /// </summary> 
    [PersistenceMode(PersistenceMode.Attribute)] 
    public string RootClass { get; set; } 

    /// <summary> 
    /// Gets or Sets the Headers link for this controls <h2> element. 
    /// </summary> 
    [PersistenceMode(PersistenceMode.Attribute)] 
    public string NavigationUrl { get; set; } 

    /// <summary> 
    /// Gets or Sets the local ID for the LayoutTemplates Placeholder control. Defaults to "layoutPlaceholder" 
    /// </summary> 
    [PersistenceMode(PersistenceMode.Attribute)] 
    public string LayoutPlaceholderID { 
     get { return string.IsNullOrWhiteSpace(this._LayoutPlaceholderID) ? "layoutPlaceholder" : this._LayoutPlaceholderID; } 
     set { this._LayoutPlaceholderID = value; } 
    } 

    [Browsable(false)] 
    [DefaultValue(null)] 
    [TemplateContainer(typeof(LayoutContainer))] 
    [PersistenceMode(PersistenceMode.InnerProperty)] 
    public ITemplate LayoutTemplate { 
     get { return _layoutTemplate; } 
     set { _layoutTemplate = value; } 
    } 

    [Browsable(false)] 
    [DefaultValue(null)] 
    [TemplateContainer(typeof(ItemContainer))] 
    [PersistenceMode(PersistenceMode.InnerProperty)] 
    public ITemplate ItemTemplate { 
     get { return _itemTemplate; } 
     set { _itemTemplate = value; } 
    } 

    #endregion Public Properties 

    public override void DataBind() { 
     if ((_itemTemplate != null) && (_layoutTemplate != null)) { 
      if (this.phContents.HasControls()) 
       this.phContents.Controls.Clear(); // Clear any existing child controls. 

      LayoutContainer parent = new LayoutContainer(this.RootClass); // Apply the RootClass only to the Root item 
      _layoutTemplate.InstantiateIn(parent); 
      PlaceHolder ph = parent.FindControl(this.LayoutPlaceholderID) as PlaceHolder; 

      if (ph == null) 
       throw new FormatException(string.Format("Unable to find the LayoutTemplate's PlaceHolder object. Either one does not exist or the name {0} specified in the LayoutPlaceholderID does not match the ID of the PlaceHolder.", this.LayoutPlaceholderID)); 

      this.RecurseBranches(this.DataSource.ToList(), ph); 
      this.phContents.Controls.Add(parent); 
     } else { 
      throw new FormatException("Both the LayoutTemplate and the ItemTemplate must be defined."); 
     } // if the template has been defined 

     base.DataBind(); 
    } 

    /// <summary> 
    /// This method will take the List of Branches and generate an unordered list with however many branches are necessary. 
    /// </summary> 
    /// <param name="Branches"></param> 
    /// <param name="Canvas"></param> 
    private void RecurseBranches(List<Branch> Branches, Control Canvas) { 
     foreach (Branch branch in Branches) { 
      ItemContainer SingleItem = new ItemContainer(branch); 
      _itemTemplate.InstantiateIn(SingleItem); 

      if (branch.HasChildren) { 
       LayoutContainer NewGroup = new LayoutContainer(); // Notice no RootClass being passed in here 
       _layoutTemplate.InstantiateIn(NewGroup); 

       PlaceHolder NewCanvas = NewGroup.FindControl(this.LayoutPlaceholderID) as PlaceHolder; 
       PlaceHolder Parent = SingleItem.FindControl(this.LayoutPlaceholderID) as PlaceHolder; 

       this.RecurseBranches(branch.Children.ToList(), NewCanvas); // Add new Items to the Group 

       Parent.Controls.Add(NewGroup); // Add the new Group to its Parent Item 
      } // if there are any children to go under this node 

      Canvas.Controls.Add(SingleItem); // Add the current Item to the Canvas 
     } // foreach of the Branches to bind 
    } // RecurseBranches - Method 

} // HeirarchicalList - Class 


#region Container Classes 

public class LayoutContainer : Control, INamingContainer { 
    public string RootClass { get; set; } 

    internal LayoutContainer() { } 
    internal LayoutContainer(string RootClass) { 
     this.RootClass = RootClass; 
    } // LayoutContainer - Constructor 
} // LayoutContainer - Class 

public class ItemContainer : Control, INamingContainer { 
    public Branch BranchItem { get; set; } 

    internal ItemContainer(Branch BranchItem) { 
     this.BranchItem = BranchItem; 
    } // ItemContainer - Constructor 

} // ItemContainer - Class 

#endregion 
}