<TelerikGrid Data=@GridData
             Pageable="true" Sortable="true" Resizable="true" Reorderable="true"
             ShowColumnMenu="true" FilterMode="@GridFilterMode.FilterMenu"
             Width="800px" Height="400px">
    <GridToolBar>
        <GridToolBarExcelExportTool>
            Export to Excel
        </GridToolBarExcelExportTool>
    </GridToolBar>
    <GridExport>
        <GridExcelExport FileName="telerik-grid-export" AllPages="false" />
    </GridExport>
    <GridColumns>
        <GridColumn Title="Personal Information">
            <Columns>
                <GridColumn Field=@nameof(Customer.FirstName) Title="First Name" Width="100px" />
                <GridColumn Field=@nameof(Customer.LastName) Title="Last Name" Width="100px" />
            </Columns>
        </GridColumn>
        <GridColumn Title="Company">
            <Columns>
                <GridColumn Field=@nameof(Customer.CompanyName) Title="Name" />
                <GridColumn Field=@nameof(Customer.HasCompanyContract) Title="Has Contract" Width="120px" />
            </Columns>
        </GridColumn>
        <GridColumn Title="Contact Details">
            <Columns>
                <GridColumn Field="@nameof(Customer.Email)" Title="Email"></GridColumn>
                <GridColumn Field="@nameof(Customer.Phone)" Title="Phone"></GridColumn>
                <GridColumn Field="@nameof(Customer.City)" Title="City"></GridColumn>
            </Columns>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

@code {
    public List<Customer> GridData { get; set; }

    public class Customer
    {
        public int Id { get; set; }
        public string PasswordHash { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string CompanyName { get; set; }
        public bool HasCompanyContract { get; set; }
        public string Email { get; set; }
        public string Phone { get; set; }
        public string City { get; set; }
    }

    // generation of dummy data
    protected override void OnInitialized()
    {
        GridData = GenerateData();
    }

    List<Customer> GenerateData()
    {
        var data = new List<Customer>();

        string[] fNames = new string[] { "Nancy", "John", "Orlando", "Jane", "Bob", "Juan" };
        string[] lNames = new string[] { "Harris", "Gates", "Smith", "Caprio", "Gash", "Gee" };
        string[] cNames = new string[] { "Acme", "Northwind", "Contoso" };
        string[] cities = new string[] { "Denver", "New York", "LA", "London", "Paris", "Helsinki", "Moscow", "Sofia" };
        Random rnd = new Random();

        for (int i = 0; i < 150; i++)
        {
            string fName = fNames[rnd.Next(0, fNames.Length)];
            string lName = lNames[rnd.Next(0, lNames.Length)];
            string cName = cNames[rnd.Next(0, cNames.Length)];
            data.Add(new Customer
            {
                Id = i,
                PasswordHash = "not shown",
                FirstName = fName,
                LastName = lName,
                CompanyName = cName,
                HasCompanyContract = i % 3 == 0,
                Email = $"{fName}.{lName}@{cName}.com",
                Phone = $"{rnd.Next(100, 999)}-555-{rnd.Next(100, 999)}",
                City = cities[rnd.Next(0, cities.Length)]
            });
        }

        return data;
    }
}