填充在GridView

Question

的rowEditing事件下拉列表我有一个GridView如下

<asp:GridView ID="gvChain" runat="server" Font-Size="Small" CellPadding="3" CellSpacing="1" GridLines="None" 
       AutoGenerateColumns="False"> 
       <HeaderStyle BackColor="#CCCCCC" /> 
       <Columns> 
        <asp:BoundField DataField="Department" HeaderText="Department" /> 
        <asp:TemplateField HeaderText="Manager Level 1"> 
         <ItemTemplate> 
          <asp:Label ID="lblManager1" runat="server" Text=""></asp:Label> 
         </ItemTemplate> 
         <EditItemTemplate> 
          <asp:DropDownList ID="cbManager1" runat="server"></asp:DropDownList> 
         </EditItemTemplate> 
        </asp:TemplateField> 
        <asp:TemplateField HeaderText="Manager Level 2"> 
         <ItemTemplate> 
          <asp:Label ID="lblManager2" runat="server" Text=""></asp:Label> 
         </ItemTemplate> 
         <EditItemTemplate> 
          <asp:DropDownList ID="cbManager2" runat="server"></asp:DropDownList> 
         </EditItemTemplate> 
        </asp:TemplateField> 
        <asp:CommandField ShowEditButton="True"> 
        <ControlStyle ForeColor="#009EDD" /> 
        </asp:CommandField> 
       </Columns> 
      </asp:GridView> 

的绑定列“系”被填充在Page_Load如下工作正常，并用列表填充的GridView部门。

Dim dhandler As DepartmentHandler = New DepartmentHandler 
    Dim depts As New List(Of Department) 
    depts = dhandler.GetDepartmentList 

    gvChain.DataSource = depts 
    gvChain.DataBind() 

然后，我在RowDAtaBound事件中填充TemplateFields的ItemTemplates，如下所示。这也工作正常。

If e.Row.RowType = DataControlRowType.DataRow Then 

     Dim lblManager1 As Label = DirectCast(e.Row.FindControl("lblManager1"), Label) 
     Dim lblManager2 As Label = DirectCast(e.Row.FindControl("lblManager2"), Label) 


     Dim eHandler As EmployeeHandler = New EmployeeHandler 
     Dim deptCell As TableCell = e.Row.Cells(0) 
     Dim dept As Department = New Department 
     dept.Department = deptCell.Text 
     Dim mgr1 As Manager = eHandler.getManager1(dept) 
     Dim mgr2 As Manager = eHandler.getManager2(dept) 

     lblManager1.Text = mgr1.Name 
     lblManager2.Text = mgr2.Name 
    End If 

我现在要实现的是对在GridView行的“编辑”字段，当点击，填充cbManager1和cbManager2与经理列表以及每个DDL的的SelectedValue设置为相同的值我正在检索项目模板。我可以在GridView的RowEditing事件与下面的代码中的数据：

' Get the list of managers 
    Dim mgrs As New List(Of Manager) 
    mgrs = eHandler.GetManagerList 

    ' Get the department name from the BoundField 
    Dim deptCell As TableCell = gvChain.Rows(e.NewEditIndex).Cells(0) 
    Dim dept As Department = New Department 
    dept.Department = deptCell.Text 

    ' Pass the department name to the getManager1/2 functions to return the correct manager for that department 
    Dim mgr1 As Manager = eHandler.getManager1(dept) 
    Dim mgr2 As Manager = eHandler.getManager2(dept) 

我已经设置断点，检查数据正在从功能回来了，数据是有预期，但我在哪里卡住在EditItemTemplate中获取DDL的引用，这样我就可以绑定它们并设置SelectedValue。我已经尝试了下面，但是这是给出一个NullReference例外：

Dim cbManager1 As DropDownList = TryCast(gvChain.Rows(e.NewEditIndex).FindControl("cbManager1"), DropDownList) 
    Dim cbManager2 As DropDownList = TryCast(gvChain.Rows(e.NewEditIndex).FindControl("cbManager2"), DropDownList) 

任何想法？

Answer 1

我到底得到了这一轮。我下面的代码添加到RowEditing事件

gvChain.EditIndex = e.NewEditIndex 
gvChain.DataBind() 

我那时中RowDataBound事件

If e.Row.RowState = DataControlRowState.Edit Then 

      Dim cbManager1 As DropDownList = TryCast(e.Row.FindControl("cbManager1"), DropDownList) 
      Dim cbManager2 As DropDownList = TryCast(e.Row.FindControl("cbManager2"), DropDownList) 

      Dim eHandler As EmployeeHandler = New EmployeeHandler 


      Dim mgrs As New List(Of Manager) 
      mgrs = eHandler.GetManagerList 
      cbManager1.DataSource = mgrs 
      cbManager2.DataSource = mgrs 
      cbManager1.DataValueField = "Name" 
      cbManager1.DataTextField = "Name" 
      cbManager2.DataValueField = "Name" 
      cbManager2.DataValueField = "Name" 
      cbManager1.DataBind() 
      cbManager2.DataBind() 

      ' Got rid of the bound field in the end and did it with a templatefield so needed to get the department from the label 
      Dim lbl As Label = e.Row.Cells(0).FindControl("lblDepartment") 
      Dim dept As Department = New Department 
      dept.Department = lbl.Text 


      Dim mgr1 As Manager = eHandler.getManager1(dept) 
      Dim mgr2 As Manager = eHandler.getManager2(dept) 


      Dim mgr1Name As String = mgr1.Name.ToUpper() 
      Dim mgr2Name As String = mgr2.Name.ToUpper() 


      cbManager1.SelectedValue = mgr1Name 
      cbManager2.SelectedValue = mgr2Name 

Answer 2

你可以尝试这样的事情

If e.Row.RowState = DataControlRowState.Edit Then 

    Dim cbmanager As DropDownList = e.Row.FindControl("cbmanager1") 

    If Not cbmanager Is Nothing Then cbmanager.Items.Add(New ListItem("Test1", "Test1")) 


End If