.NET Show roles in DropDownList within GridView

Hi. I am new to .NET so please be obvious and detailed in your answers!
I am trying to implement both Membership and Roles in a system using SQL Server Express.
Membership so far is working OK. I'm building a web interface to manage the assignment of roles which users belong to.

I want a list of all my users in a GridView - with paging. At the moment, I have their username, email, date created, and an empty dropdownlist showing for all the users, in a paging gridview.

To build on what I currently have, I need three things:

1) Populate the dropdownlist of each row with all the roles in the system
2) Set the dropdownlist to display for each row (or "user") the role they are part of.
3) On changing the dropdownlist, postback and update the roles table accordingly.

Attached is the current code below. I appreciate this is a lot of work so will award points accordingly. I just have no idea about how to go about this.

Chris


<asp:GridView ID="EntireUserList" runat="server" AutoGenerateColumns="False" AlternatingRowStyle-BackColor="#BFCFFF" BackColor="White" Width="100%" HeaderStyle-BackColor="#809FFF" HeaderStyle-Font-Italic="False" HeaderStyle-HorizontalAlign="Center" BorderWidth="1" BorderStyle="Solid" BorderColor="Black">
        <Columns> 
                    <asp:BoundField DataField="UserName" HeaderText="Username" />
                    <asp:BoundField DataField="Email" HeaderText="Email" />
                    <asp:BoundField DataField="CreationDate" HeaderText="Date Created" />
          <asp:TemplateField HeaderText="Assigned Role">
          <ItemTemplate>
          <asp:DropDownList ID="RoleDropdown" runat="server" AutoPostBack="True"></asp:DropDownList>
          </ItemTemplate>
          </asp:TemplateField>
          </Columns> 
        </asp:GridView>

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chris_smith_51Asked:
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carlnorrbomCommented:
Hi,

Look at the attached code to see how you can do what you want! What you need to keep in mind, your app logic will break if a user belongs to more than one group! I have added logic to clear group membership before assigning a new group in order for the app logic not to break. To summarize the key components:

1. In your markup you need to add: OnSelectedIndexChanged="RoleDropdown_SelectedIndexChanged" to the declarative code for your dropdown.

2. I have abstracted out the membership user collecting and binding of the gridview to a private sub: BindAllUsers()

3. The collecting of all available roles and adding them as items to the dropdowns is taken care of in the EntireUserList_RowDataBound event for each row. This could be optimized further by loading available roles into a session variable for instance. Also, the code will break if a user has NOT been assigned a role on the following line of code: ddlRoles.SelectedValue = Roles.GetRolesForUser(u.UserName)(0).ToString() - it will throw an IndexOutOfRange exception. You might want to add for instance a try catch block or whatever.

4. The updating of role assignment for the users are done in the RoleDropdown_SelectedIndexChanged event.

Hope this helps!

/Carl.
MembershipAdministration.aspx:
 
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="MembershipAdministration.aspx.vb"
    Inherits="MembershipAdministration" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="EntireUserList" runat="server" AutoGenerateColumns="False" AlternatingRowStyle-BackColor="#BFCFFF"
            BackColor="White" Width="100%" HeaderStyle-BackColor="#809FFF" HeaderStyle-Font-Italic="False"
            HeaderStyle-HorizontalAlign="Center" BorderWidth="1" BorderStyle="Solid" BorderColor="Black">
            <Columns>
                <asp:BoundField DataField="UserName" HeaderText="Username" />
                <asp:BoundField DataField="Email" HeaderText="Email" />
                <asp:BoundField DataField="CreationDate" HeaderText="Date Created" />
                <asp:TemplateField HeaderText="Assigned Role">
                    <ItemTemplate>
                        <asp:DropDownList ID="RoleDropdown" runat="server" AutoPostBack="True" OnSelectedIndexChanged="RoleDropdown_SelectedIndexChanged">
                        </asp:DropDownList>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </div>
    </form>
</body>
</html>
 
MembershipAdministration.aspx.vb:
 
Imports System.Data
 
 
Partial Class MembershipAdministration
    Inherits System.Web.UI.Page
 
    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        BindAllUsers(EntireUserList)
    End Sub
 
    Protected Sub EntireUserList_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles EntireUserList.RowDataBound
        If e.Row.RowType = DataControlRowType.DataRow Then
            Dim u As MembershipUser = Membership.GetUser(e.Row.Cells(0).Text.ToString())
            Dim rolesCollection As String() = Roles.GetAllRoles()
            Dim ddlRoles As DropDownList = CType(e.Row.FindControl("RoleDropdown"), DropDownList)
            For Each role As String In rolesCollection
                ddlRoles.Items.Add(New ListItem(role.ToString(), role.ToString()))
            Next
            ddlRoles.SelectedValue = Roles.GetRolesForUser(u.UserName)(0).ToString()
        End If
    End Sub
 
    Protected Sub RoleDropdown_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
        Dim row As GridViewRow = CType(CType(CType(sender, DropDownList).Parent, DataControlFieldCell).Parent, GridViewRow)
        Dim u As MembershipUser = Membership.GetUser(row.Cells(0).Text.ToString())
        Roles.RemoveUserFromRole(u.UserName.ToString(), Roles.GetRolesForUser(u.UserName.ToString())(0)) 'this is needed to not break you app logic!
        Roles.AddUserToRole(u.UserName.ToString(), CType(sender, DropDownList).SelectedValue.ToString())
        BindAllUsers(EntireUserList)
    End Sub
 
    Private Sub BindAllUsers(ByVal gv As GridView)
        Dim users As MembershipUserCollection = Membership.GetAllUsers()
        Dim dtUsers As New DataTable()
        dtUsers.Columns.Add("UserName", GetType(System.String))
        dtUsers.Columns.Add("Email", GetType(System.String))
        dtUsers.Columns.Add("CreationDate", GetType(System.DateTime))
        Dim objUser(2) As Object
        For Each u As MembershipUser In users
            objUser(0) = u.UserName.ToString()
            objUser(1) = u.Email.ToString()
            objUser(2) = u.CreationDate
            dtUsers.Rows.Add(objUser)
        Next
        gv.DataSource = dtUsers
        gv.DataBind()
    End Sub
 
End Class

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chris_smith_51Author Commented:
perfect! thanks so much!
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