getting error when tring to update user details, asp.net membership

I am using asp.net membership and trying to update a users details but get the following error:

Error    2    Overload resolution failed because no accessible 'New' accepts this number of arguments. 

Below is the full .vb code:

Partial Class FamilyAdmin_edit_user
    Inherits System.Web.UI.Page

    Private username As String

    Dim user As MembershipUser

    Private Sub Page_Load()
        username = Request.QueryString("username")
        If username Is Nothing OrElse username = "" Then
            Response.Redirect("users.aspx")
        End If
        User = Membership.GetUser(username)

        UserUpdateMessage.Text = ""
    End Sub

    Protected Sub UserInfo_ItemUpdating(ByVal sender As Object, ByVal e As DetailsViewUpdateEventArgs)
        'Need to handle the update manually because MembershipUser does not have a
        'parameterless constructor  

        user.Email = DirectCast(e.NewValues(0), String)
        user.Comment = DirectCast(e.NewValues(1), String)
        user.IsApproved = CBool(e.NewValues(2))

        Try
            ' Update user info:
            Membership.UpdateUser(user)

            ' Update user roles:
            UpdateUserRoles()

            UserUpdateMessage.Text = "Update Successful."

            e.Cancel = True
            UserInfo.ChangeMode(DetailsViewMode.[ReadOnly])
        Catch ex As Exception
            UserUpdateMessage.Text = "Update Failed: " + ex.Message

            e.Cancel = True
            UserInfo.ChangeMode(DetailsViewMode.[ReadOnly])
        End Try
    End Sub

    Private Sub Page_PreRender()
        ' Load the User Roles into checkboxes.
        UserRoles.DataSource = Roles.GetAllRoles()
        UserRoles.DataBind()

        ' Disable checkboxes if appropriate:
        If UserInfo.CurrentMode <> DetailsViewMode.Edit Then
            For Each checkbox As ListItem In UserRoles.Items
                checkbox.Enabled = False
            Next
        End If

        ' Bind these checkboxes to the User's own set of roles.
        Dim userRoles__1 As String() = Roles.GetRolesForUser(username)
        For Each role As String In userRoles__1
            Dim checkbox As ListItem = UserRoles.Items.FindByValue(role)
            checkbox.Selected = True
        Next
    End Sub

    Private Sub UpdateUserRoles()
        For Each rolebox As ListItem In UserRoles.Items
        开发者_如何学JAVA    If rolebox.Selected Then
                If Not Roles.IsUserInRole(username, rolebox.Text) Then
                    Roles.AddUserToRole(username, rolebox.Text)
                End If
            Else
                If Roles.IsUserInRole(username, rolebox.Text) Then
                    Roles.RemoveUserFromRole(username, rolebox.Text)
                End If
            End If
        Next
    End Sub

    Public Sub DeleteUser(ByVal sender As Object, ByVal e As EventArgs)
        'Membership.DeleteUser(username, false); // DC: My apps will NEVER delete the related data.
        Membership.DeleteUser(username, True)
        ' DC: except during testing, of course!
        Response.Redirect("manage_members.aspx")
    End Sub

    Public Sub UnlockUser(ByVal sender As Object, ByVal e As EventArgs)
        ' Dan Clem, added 5/30/2007 post-live upgrade.

        ' Unlock the user.
        User.UnlockUser()

        ' DataBind the GridView to reflect same.
        UserInfo.DataBind()
    End Sub

End Class

Before i had:

 Dim user As MembershipUser

and got the error:

Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 20: 'parameterless constructor Line 21: Line 22:

user.Email = DirectCast(e.NewValues(0), String) Line 23: user.Comment = DirectCast(e.NewValues(1), String) Line 24: user.IsApproved = CBool(e.NewValues(2))

I apologise for my lack of programming knowledge. Could you please point out where i need to change my code to be able to update the users details?

Thanks

In Membership.GetUser(username) you need to add a second parameter IsUserOnline (Boolean): Membership.GetUser(username, true)

The variable Membership is initialized with a Membership.Provider?