Owl's Blog on .NET development

Component Owl codes Better ListView control all night so you don't have to.

Sub-item Check Boxes in Better ListView

Better ListView Sub-item Check Boxes

Better ListView Sub-item Check Boxes

Better ListView 3.10.0 allows displaying fully interactive check boxes and even radio buttons in sub-item cells.

This feature can be activated simply by setting CheckBoxAppearance property of a given sub-item to other value than Hide. Such sub-item will not display check box or radio instead of image and text.

Please note the first sub-item’s properties do not apply as they are overriden by item’s properties. These two are separate for the case of column reordering (keeping consistency of sub-item states).

Another new feature in Better ListView is that check boxes or radios can be displayed disabled. This can be achieved by setting CheckEnabled property to false on the respective item or sub-item.

Sub-item check boxes can be operated by both mouse and keyboard. Checking sub-item with keyboard can be done by navigating focus rectangle by arrow keys to the given sub-item and pressing spacebar.

How to Add Grid Lines in Empty Space in Better ListView

Default list without grid lines below items

Default list without grid lines below items

List with grid lines added

List with grid lines added

Setting grid lines in Better ListView is easy. Simply make sure you are using Details view (the default view). Then you can set GridLines property to one of the following values:

  • None – grid lines are hidden
  • Horizontal – only horizontal lines are displayed
  • Vertical – only vertical lines are displayed
  • Grid – both horizontal and vertical lines are displayed, forming a grid

None of these settings, however, cause drawing lines below the last visible item, which may be desirable. The reason for this is that Better ListView supports custom item height and there is uncertainity about the spacing between new grid lines (smallest?, largest?, average?) It is up to your choice.

To draw new grid lines, handle the DrawBackground event (or subclass BetterListView and override the OnDrawBackground method) with the following code:

[csharp gutter=”false” toolbar=”false”]
private void ListViewOnDrawBackground(object sender, BetterListViewDrawBackgroundEventArgs eventArgs)
{
BetterListView listView = (BetterListView)sender;

// get last visible item
var item = listView.BottomItem;

if (item == null)
{
return;
}

// measure row height
var bounds = listView.GetItemBounds(item);
int rowHeight = bounds.BoundsOuterExtended.Height;

// draw additional lines
Rectangle rectClient = listView.ClientRectangleInner;
Pen penGridLines = new Pen(listView.ColorGridLines, 1.0f);

int y = (bounds.BoundsOuterExtended.Bottom + rowHeight);

while (y < rectClient.Bottom) { eventArgs.Graphics.DrawLine( penGridLines, rectClient.Left, y, rectClient.Right - 1, y); y += rowHeight; } penGridLines.Dispose(); } [/csharp] What this code does is getting the last visible item using BottomItem property. It is importantĀ  to get this visible item instead of e.g. first item because GetItemBounds method returns non-null value on visible items only. The GetItemBounds method reveals item measurement which is used to determine item height and coordinate of its bottom. Finally, we draw new lines using current grid line colorĀ  (ColorGridLines property) until reaching the bottom of the view.