
Chapter 6: Using Lists and Tree Views in a Window
Pictures for items
There are several ways to use pictures in a TreeView. You
associate a picture in one of the picture lists with an item by
setting one of the item’s picture properties, described
in Table 6-9.
Table 6-9: TreeView picture properties
Property
|
Purpose
|
PictureIndex
|
The primary picture associated with the
item is displayed just to the left of the item’s label.
|
StatePictureIndex
|
A state picture is displayed to the left
of the regular picture. The item moves to the right to make room
for the state picture. If the Checkboxes property is true,
the state picture is replaced by a pair of check boxes.
Because a state picture takes up room, items without state pictures
will not align with items that have pictures. So that all items
have a state picture and stay aligned, you can use a blank state
picture for items that do not have a state to be displayed.
A use for state pictures might be to display a check mark beside
items the user has chosen.
|
OverlayPictureIndex
|
An overlay picture is displayed on top
of an item’s regular picture.
You set up the overlay picture list in a script by designating a
picture in the regular picture list for the overlay picture list.
An overlay picture is the same size as a regular picture,
but it often uses a small portion of the image space so that it
only partially covers the regular picture. A typical use of overlay pictures
is the arrow marking shortcut items in the Windows Explorer.
|
SelectedPictureIndex
|
A picture from the regular picture list
that is displayed in place of the regular picture when the item
is the current item. When the user selects another item, the first
item gets its regular picture and the new item displays its selected picture.
If you do not want a different picture when an item is current,
set SelectedPictureIndex to the same value as PictureIndex.
|
How to set pictures You can change the pictures for all items at a particular level
with the SetLevelPictures function, or you can
set the picture properties for an individual item.
If you do not want pictures Your TreeView does not have to use pictures for items. If
an item’s picture indexes are 0, no pictures are displayed.
However, the TreeView always leaves room for the regular picture.
You can set the PictureWidth property to 0 to eliminate that
space:
tv_2.DeletePictures()
tv_2.PictureWidth = 0
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