TreeList.CustomDrawNodePreview Event

Allows you to custom paint preview sections.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v20.1.dll

Declaration

[DXCategory("CustomDraw")]
public event CustomDrawNodePreviewEventHandler CustomDrawNodePreview
<DXCategory("CustomDraw")>
Public Event CustomDrawNodePreview As CustomDrawNodePreviewEventHandler

Event Data

The CustomDrawNodePreview event's data class is CustomDrawNodePreviewEventArgs. The following properties provide information specific to this event:

Property Description
Appearance Gets the painted element's appearance settings. Inherited from CustomDrawEventArgs.
Bounds Gets the painted element's bounding rectangle. Inherited from CustomDrawEventArgs.
Cache Gets an object specifying the storage for the most used pens, fonts and brushes. Inherited from CustomDrawEventArgs.
Graphics Gets an object used to paint. 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.
IsRightToLeft Gets a value indicating whether the TreeList's elements are aligned to support locales using right-to-left fonts. Inherited from CustomDrawEventArgs.
ObjectArgs Gets an object containing information about the painted element. Inherited from CustomDrawEventArgs.
Painter Gets the painter object that provides the default element's painting mechanism. Inherited from CustomDrawEventArgs.
PreviewText Gets or sets the painted preview section's text.

Remarks

See the Custom Draw Scenarios topic 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.

Examples

The following sample code handles the TreeList.CustomDrawNodePreview event. It is used to perform custom painting of preview sections.

The image below displays the result of sample code execution.

CustomDraw - NodePreview

using System.Drawing;
using System.Drawing.Drawing2D;
using DevExpress.XtraTreeList

private void treeList1_CustomDrawNodePreview(object sender, CustomDrawNodePreviewEventArgs e) {
    // filling background with a linear gradient brush
    Brush backBrush = e.Cache.GetGradientBrush(e.Bounds, Color.LightGoldenrodYellow, Color.Cornsilk, LinearGradientMode.Vertical);
    e.Cache.FillRectangle(backBrush, e.Bounds);
    // painting the preview string
    e.Appearance.FontStyleDelta = FontStyle.Italic;
    e.Cache.DrawString(e.PreviewText, e.Appearance.Font, Brushes.Maroon, e.Bounds, e.Appearance.GetStringFormat());
    // prohibiting default painting
    e.Handled = true;
}
See Also