DiagramControl.CustomDrawBackground Event

Occurs before the Canvas background is rendered.

Namespace: DevExpress.XtraDiagram

Assembly: DevExpress.XtraDiagram.v19.1.dll

Declaration

C#

[DiagramCategory(DiagramCategory.DiagramPaint)]
public event EventHandler<CustomDrawBackgroundEventArgs> CustomDrawBackground

VB.NET

<DiagramCategory(DiagramCategory.DiagramPaint)>
Public Event CustomDrawBackground As EventHandler(Of CustomDrawBackgroundEventArgs)

Event Data

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

Property	Description
ContentBounds	Gets the rectangle which encompasses the background area excluding margins.
Context	Gets whether the item is to be drawn on the canvas, toolbox, in the print or export output or as the drag preview.
Graphics	Returns an object that provides painting facilities.
PagesInfo	Gets the list of diagram pages.
PrintBounds	Gets the rectangle which encompasses the total background area when printing the diagram.
PrintClientBounds	Gets the rectangle which encompasses the background area excluding margins when printing the diagram.
PrintIndex	Gets the zero-based index of the page that is currently being rendered when printing the diagram.
TotalBounds	Gets the rectangle which encompasses the total background area.
ViewportBounds	Gets the rectangle which encompasses the viewport area.

Remarks

Use the CustomDrawBackground event to draw a custom Canvas background.

The following code snippet illustrates how to set an image as the diagram background:

C#

private void DiagramControl_CustomDrawBackground(object sender, CustomDrawBackgroundEventArgs e) {
    if (e.Context != DiagramDrawingContext.Print)
        e.Graphics.DrawImage(Image.FromFile("Images\\background.jpg"), e.TotalBounds);
}

VB.NET

Private Sub DiagramControl_CustomDrawBackground(ByVal sender As Object, ByVal e As CustomDrawBackgroundEventArgs)
    If e.Context <> DiagramDrawingContext.Print Then
        e.Graphics.DrawImage(Image.FromFile("Images\background.jpg"), e.TotalBounds)
    End If
End Sub

Note

If the font’s Unit property is not set to GraphicsUnit.Pixel, the font size of the text drawn by the Graphics.DrawString method is scaled based on the DPI settings.