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BandedGridView.CustomDrawBandHeader Event

Enables you to custom paint band headers.

Namespace: DevExpress.XtraGrid.Views.BandedGrid

Assembly: DevExpress.XtraGrid.v19.1.dll

Declaration

[DXCategory("CustomDraw")]
public event BandHeaderCustomDrawEventHandler CustomDrawBandHeader

Event Data

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

Property Description
Appearance Gets the painted element’s appearance settings. Inherited from CustomDrawEventArgs.
Band Gets the band whose header is to be painted. Returns null if an “empty band header” is currently being painted.
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.
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 View information for the band header being painted.
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.

Remarks

The CustomDrawBandHeader event fires when a band header is about to be painted. See the Custom Painting Basics and Custom Painting Scenarios topics for information on using custom draw events.

IMPORTANT

Never change cell values or modify the control’s layout on this event, or any other event designed to tune the control’s appearance. Any action that causes a layout update can cause the control to malfunction.

Examples

The following code handles the BandedGridView.CustomDrawBandHeader event to paint band headers with a 3D effect in the pressed state.

CustomDrawBandHeader_2

private void bandedGridView1_CustomDrawBandHeader(object sender, DevExpress.XtraGrid.Views.BandedGrid.BandHeaderCustomDrawEventArgs e) {
    if (e.Band == null) return;
    if (e.Info.State != ObjectState.Pressed) return;
    using (Brush brushPressed = new LinearGradientBrush(e.Bounds, Color.WhiteSmoke, Color.Gray, LinearGradientMode.ForwardDiagonal)) {
        Rectangle r = e.Bounds;
        Draw3DBorder(e.Cache, r);
        r.Inflate(-1, -1);
        //Fill the background
        e.Cache.FillRectangle(brushPressed, r);

        //Draw a band glyph
        foreach (DrawElementInfo info in e.Info.InnerElements) {
            if (!info.Visible) continue;
            GlyphElementInfoArgs glyphInfoArgs = info.ElementInfo as GlyphElementInfoArgs;
            if (glyphInfoArgs == null) continue;
            info.ElementInfo.OffsetContent(1, 1);
            ObjectPainter.DrawObject(e.Cache, info.ElementPainter, info.ElementInfo);
            info.ElementInfo.OffsetContent(-1, -1);
            break;
        }

        //Draw the band's caption with a shadowed effect
        Rectangle textRect = e.Info.CaptionRect;
        textRect.Offset(2, 2);
        e.Appearance.DrawString(e.Cache, e.Info.Caption, textRect, Brushes.White);
        textRect.Offset(-1, -1);
        e.Appearance.DrawString(e.Cache, e.Info.Caption, textRect, Brushes.Black);

        //Prevent default painting
        e.Handled = true;
    }
}

private void Draw3DBorder(GraphicsCache cache, Rectangle rect) {
    //Draw a 3D border
    BorderPainter painter = BorderHelper.GetPainter(DevExpress.XtraEditors.Controls.BorderStyles.Style3D);
    AppearanceObject borderAppearance = new AppearanceObject();
    borderAppearance.BorderColor = Color.DarkGray;
    painter.DrawObject(new BorderObjectInfoArgs(cache, borderAppearance, rect));
}
See Also