Question

I’m trying to put together a custom user update page so you can update a user’s email, password and role all on one page. I’m stuck on the roles. I have listed the roles ok, but I want to select the role allocated to the user in a listbox.

In this case each user will only have one role.

I’ve tried playing around with Roles.GetRolesForUser("userName"); without much luck.

Here’s the listbox code:

<asp:ListBox ID="myRoles" runat="server"
     SelectionMode="Single" >
</asp:ListBox>

And here’s the databinding for the Listbox:

rolesArray = Roles.GetAllRoles();
myRoles.DataSource = rolesArray;
myRoles.DataBind();

What’s the easiest to get this to work?

Answer 1

protected void Page_Load(object sender, EventArgs e)
    {
        var allRoles = new[] {"Admin", "Client", "Super Admin", "Other"};

        //Returns string array
        var rolesByUser = Roles.GetRolesForUser(HttpContext.User.Identity.Name);

        myRoles.DataSource = allRoles;
        myRoles.DataBind();

        foreach (ListItem role in myRoles.Items)
        {
            foreach (var userRole in rolesByUser)
            {
                if (role.Text == userRole)
                    role.Selected = true;
            }
        }
    }

Then in your html:

<asp:ListBox ID="myRoles" SelectionMode="Multiple" runat="server"></asp:ListBox>

Single Role/Single Selection Only

Change loop to :

foreach (ListItem role in myRoles.Items)
        {
            if (role.Text == rolesByUser.FirstOrDefault())
                role.Selected = true;
        }

Alternatives

Here’s a shorter version of that loop using LINQ to Objects:

    foreach (ListItem role in myRoles.Items)
            {
                foreach (var userRole in rolesByUser
                                    .Where(userRole => role.Text == userRole))
                {
                    role.Selected = true;
                }
            }

And finally a pure LINQ mode that is in my opinion a bit too hard to read:

foreach (ListItem role in from ListItem role in myRoles.Items 
                from userRole in rolesByUser.Where(userRole => role.Text == userRole) 
                select role)
        {
            role.Selected = true;
        }