Owl's Blog on .NET development

Customized item selection.

By default, Better ListView uses system theme for drawing selections.

To draw custom selection, you can use owner drawing capabilities of Better ListView:

C#

[csharp gutter=”false” toolbar=”false”]
class CustomListView : BetterListView
{
protected override void OnDrawItemBackground(BetterListViewDrawItemBackgroundEventArgs eventArgs)
{
base.OnDrawItemBackground(eventArgs);

if (eventArgs.Item.Selected)
{
Brush brushSelection = new SolidBrush(Color.FromArgb(128, Color.LightGreen));
eventArgs.Graphics.FillRectangle(brushSelection, eventArgs.ItemBounds.BoundsSelection);
brushSelection.Dispose();
}
}

protected override void OnDrawItem(BetterListViewDrawItemEventArgs eventArgs)
{
eventArgs.DrawSelection = false;

base.OnDrawItem(eventArgs);

if (eventArgs.Item.Selected)
{
eventArgs.Graphics.DrawRectangle(Pens.DarkGreen, eventArgs.ItemBounds.BoundsSelection);
}
}
}
[/csharp]

Visual Basic

[vb gutter=”false” toolbar=”false”]
Class CustomListView
Inherits BetterListView
Protected Overrides Sub OnDrawItemBackground(eventArgs As BetterListViewDrawItemBackgroundEventArgs)
MyBase.OnDrawItemBackground(eventArgs)

If eventArgs.Item.Selected Then
Dim brushSelection As Brush = New SolidBrush(Color.FromArgb(128, Color.LightGreen))
eventArgs.Graphics.FillRectangle(brushSelection, eventArgs.ItemBounds.BoundsSelection)
brushSelection.Dispose()
End If
End Sub

Protected Overrides Sub OnDrawItem(eventArgs As BetterListViewDrawItemEventArgs)
eventArgs.DrawSelection = False

MyBase.OnDrawItem(eventArgs)

If eventArgs.Item.Selected Then
eventArgs.Graphics.DrawRectangle(Pens.DarkGreen, eventArgs.ItemBounds.BoundsSelection)
End If
End Sub
End Class
[/vb]

In the above code, we have created class CustomListView that inherits from BetterListView. We override OnDrawItemBackground and OnDrawItem methods to customize item background and item foreground drawing, respectively.

The OnDrawItemBackground method contains only check for whether the item is selected. If so, we draw selection background (filled rectangle in selection area).

The OnDrawItem method contains two things:

1. Turn off  default selection.
2. Draw custom selection border if the item is selected.

Drawbacks of drawing custom selections like this include using non-system theme, which can look ugly on various color schemes. By default, Better ListView always use the system theme, so the color consistency is ensured. You can, however, still use classes like SystemColors or SystemBrushes to ensure good look.

Another drawback is that you handle only two states of selection, i.e. selected and unselected state. This is sufficient for Classic Windows theme but there are several more states used on Windows Aero Theme, like “hot”, “focused and hot” or “hot and pressed”.

To allow these states, considerable coding need to be done.

In case you need this level of customization, please contact us for Custom Coding support.