There is relationship between LCE Category and LCE Type. The items of LCE Type are gotten dynamically according to the selected item of LCE Category. When the certain item of LCE Category is chosen, the system will get dataset from the database via Store Procedure. The items of LCE Type will be updated.

Now let I explain the implementation using the traditional way in ASP.NET.

1.      Set ASPX

LCECategoryTypeDropDownList should set AutoPostBack attribute to TRUE.

<asp:TemplateField HeaderText="LCE Category" >

<ItemTemplate>

<asp:DropDownList ID="LCECategoryTypeDropDownList" runat="server" AutoPostBack="true"></asp:DropDownList>

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="LCE Type" >

<ItemTemplate>

    <asp:DropDownList ID="LCETypeDropDownList" runat="server" ></asp:DropDownList>

</ItemTemplate>

</asp:TemplateField>

 

2.      Set behind code

 

Please note, the AddHandler statement must be put in the RowCreated Method. If you put it into the RowDataBound method instead, it doesn’t work.

Private Sub profileDetailGridView_RowCreated(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles profileDetailGridView.RowCreated

Dim LCECategoryTypeDropDownList As DropDownList

 

If e.Row.RowType = DataControlRowType.DataRow Then

LCECategoryTypeDropDownList = CType(e.Row.FindControl("LCECategoryTypeDropDownList"), DropDownList)

 

           

AddHandler LCECategoryTypeDropDownList.SelectedIndexChanged, AddressOf CategoryTypeDropDownList_SelectedIndexChanged

      End If

End Sub

 

I quote Parent twice in the following snippet. The first Parent is to get Cell which includes current DropDowList. The second Parent is to get Parent of Cell, Row.

Protected Sub CategoryTypeDropDownList_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)

 

Dim CategoryDropDownList As DropDownList = CType(sender, DropDownList)

      Dim LCETypeDropDownList As DropDownList

 

      If CategoryDropDownList IsNot Nothing Then

        LCETypeDropDownList = CType(CategoryDropDownList.Parent.Parent.FindControl("LCETypeDropDownList"), DropDownList)

     

‘’’ get dataset and bind to the controls

 

      End If

End Sub

 

If you have any questions, please feel free to let me know.

Thanks.