<DataGrid Name="dgUsers" Height="150"
    CellEditEnding="dgUsers_CellEditEnding">
</DataGrid>

<StackPanel Name="spActions" Background="#2d2d30" Width="500" Height="50" Orientation="Horizontal" FlowDirection="RightToLeft">
    <Button Name="btnCancel" Click="btnClose_Click" Content="Cancel" Style="{StaticResource CancelButton}" Height="30" Width="66" Margin="5,3,5,5"></Button>
    <Button Name="btnSave" Click="btnSave_Click" Content="Save" Style="{StaticResource RoundedButtonGreen}" Height="30" Width="66" Margin="5,3,5,5"></Button>
    <Label Name="lblResult"></Label>
</StackPanel>

private List<User> UpdatedUsers { get; set; }
/// <summary>
/// Maintains a list of all changes made to all entities on the datagrid
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void dgUsers_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
{
    if (UpdatedUsers == null) UpdatedUsers= new List<User>();

    var _User = (User)e.Row.Item;
    var Element = (TextBox)e.EditingElement;
    if (String.Equals((string)e.Column.Header, "EmailAddress"))
    {
        User.EmailAddress = Element.Text;
    }
    else if (String.Equals((string)e.Column.Header, "Password"))
    {
        User.Password = Element.Text;
    }

    UpdatedUsers.Add(User);
}

private void btnSave_Click(object sender, RoutedEventArgs e)
{
    try
    {
        ApplicationDbContext Context = new ApplicationDbContext();
        var Users = Context.Users.Where(x => x.CompanyId == (int)cmbCompanies.SelectedValue).ToList();

        foreach (User User in Users)
        {
            foreach (User U in UpdatedUsers)
            {
                if (U.Id == User.Id)
                {
                    User.EmailAddress = U.EmailAddress;
                    User.Password = U.Password;
                }
                Context.SaveChanges();
            }
        }
    }
    catch (Exception ex)
    {
        lblResult.Content = ex.Message;
    }
}