GridView.CustomDrawColumnHeader Event
Enables you to paint column headers manually.
Namespace: DevExpress.XtraGrid.Views.Grid
Assembly: DevExpress.XtraGrid.v24.1.dll
NuGet Packages: DevExpress.Win.Grid, DevExpress.Win.Navigation
Declaration
[DXCategory("CustomDraw")]
public event ColumnHeaderCustomDrawEventHandler CustomDrawColumnHeaderEvent Data
The CustomDrawColumnHeader event's data class is ColumnHeaderCustomDrawEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| Appearance | Gets the painted element’s appearance settings. Inherited from CustomDrawEventArgs. |
| Bounds | Returns a value specifying limits for the drawing area. Inherited from CustomDrawEventArgs. |
| Cache | Provides methods to paint on drawing surfaces in GDI+ and DirectX modes. See DirectX hardware acceleration to learn more. Inherited from CustomDrawEventArgs. |
| Column | Gets the GridColumn whose header is to be drawn. Returns null if an “empty column header” is currently being painted. |
| Graphics | A GDI+ drawing surface. Use the CustomDrawEventArgs.Cache property instead if you enable the DirectX hardware acceleration. Inherited from CustomDrawEventArgs. |
| Handled | Gets or sets a value specifying whether an event was handled and that the default element painting is therefore not required. Inherited from CustomDrawEventArgs. |
| Info | Gets an object providing information necessary to paint a column header. |
| Painter | Gets the painter object that provides the default element painting mechanism. Inherited from CustomDrawObjectEventArgs. |
The event data class exposes the following methods:
| Method | Description |
|---|---|
| DefaultDraw() | Performs default painting of an element. Inherited from CustomDrawEventArgs. |
| DrawHtml(HtmlTemplate, DxHtmlPainterContext, Action<DxHtmlPainterArgs>) | Paints the required HTML template inside an element that raised this event. The context parameter allows you to assign an object that transfers mouse events to template elements. Inherited from CustomDrawEventArgs. |
| DrawHtml(HtmlTemplate, Action<DxHtmlPainterArgs>) | Paints the required HTML template inside an element that raised this event. Inherited from CustomDrawEventArgs. |
Remarks
The CustomDrawColumnHeader event is raised each time a column header is about to be painted. The column is identified by the ColumnHeaderCustomDrawEventArgs.Column parameter. See the Custom Painting Basics and Custom Painting Scenarios topics for information on using custom draw events.
Important
Do not change cell values, modify the control’s layout, or change the control’s object model in the events used for custom control painting. Actions that update the layout can cause the control to malfunction.
Example
This example demonstrates how to fill the “Category_Name” column header with the Coral color.
using DevExpress.Utils;
using DevExpress.Utils.Drawing;
using DevExpress.XtraGrid;
using DevExpress.XtraGrid.Views.Grid;
private void Form3_Load1(object sender, EventArgs e) {
CustomDrawColumnHeader(gridControl1, gridView1);
}
public static void CustomDrawColumnHeader(GridControl gridControl, GridView gridView) {
// Handle this event to paint columns headers manually
gridView.CustomDrawColumnHeader += (s, e) => {
if (e.Column == null || e.Column.FieldName != "Category_Name")
return;
// Fill column headers with the specified colors.
e.Cache.FillRectangle(Color.Coral, e.Bounds);
e.Appearance.DrawString(e.Cache, e.Info.Caption, e.Info.CaptionRect);
// Draw the filter and sort buttons.
foreach (DrawElementInfo info in e.Info.InnerElements) {
if (!info.Visible) continue;
ObjectPainter.DrawObject(e.Cache, info.ElementPainter, info.ElementInfo);
}
e.Handled = true;
};
}
Related GitHub Examples
The following code snippets (auto-collected from DevExpress Examples) contain references to the CustomDrawColumnHeader event.
Note
The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.