# HeaderCellRender

The [ASP NET AJAX Calendar](https://www.telerik.com/products/aspnet-ajax/calendar.aspx) control provides the
**HeaderCellRender** server event, which is raised after all the
row and column headers and the view selector have been generated and just
before one of these header cells is rendered to the client. It is the last
place where changes to the already constructed header cells can be made.

> note
> The **HeaderCellRender** event does not fire if the calendar does not display its row and column headers or view selectors. That is, if the **ShowRowHeaders**, **ShowColumnHeaders** and **EnableViewSelector** properties are all **False**, the event does not fire.

The **HeaderCellRender** event handler has two arguments:

1. The **RadCalendar** control whose header cell is about to be rendered. This argument is of type object, but can be cast to the **RadCalendar** type.

2. A **HeaderCellRenderEventArgs** object. This object has the following two properties:

   * **Cell** is the control for the cell that is about to be rendered. The event handler can make changes to this control to change the way the cell is rendered.

   * **HeaderType** is an enumerated value that indicates whether the cell represents a row header, column header, or view selector.

Use the **HeaderCellRender** event handler to make changes to the header cell before it is rendered:

```C#
protected void RadCalendar1_HeaderCellRender(object sender, HeaderCellRenderEventArgs e)
{
    switch (e.HeaderType)
    {
        case Telerik.Web.UI.Calendar.HeaderType.Column:
            e.Cell.BackColor = System.Drawing.Color.Red;
            break;
        case Telerik.Web.UI.Calendar.HeaderType.Row:
            e.Cell.BackColor = System.Drawing.Color.Green;
            break;
        case Telerik.Web.UI.Calendar.HeaderType.View:
            e.Cell.BackColor = System.Drawing.Color.White;
            break;
    }
}
```

```VB.NET
Protected Sub RadCalendar1_HeaderCellRender(ByVal sender As Object, ByVal e As HeaderCellRenderEventArgs) Handles RadCalendar1.HeaderCellRender
    Select Case e.HeaderType
        Case Telerik.Web.UI.Calendar.HeaderType.Column
            e.Cell.BackColor = System.Drawing.Color.Red
            Exit Select
        Case Telerik.Web.UI.Calendar.HeaderType.Row
            e.Cell.BackColor = System.Drawing.Color.Green
            Exit Select
        Case Telerik.Web.UI.Calendar.HeaderType.View
            e.Cell.BackColor = System.Drawing.Color.White
            Exit Select
    End Select
End Sub
```

## See Also

* [DayRender](https://www.telerik.com/products/aspnet-ajax/documentation/controls/calendar/server-side-programming/events/dayrender)