You can add pictures to the regular and state picture lists in the painter or during execution. During execution, you can assign pictures in the regular picture list to the overlay list.
The mask color is a color used in the picture that becomes transparent when the picture is displayed. Usually you should pick the picture’s background color so that the picture blends with the color of the TreeView.
Before you add a picture, in the painter or in a script, you can set the mask color to a color appropriate for that picture. This statement sets the mask color to white, which is right for a picture with a white background:
tv_1.PictureMaskColor = RGB(255, 255, 255)
Each picture can have its own mask color. A picture uses the color that is in effect when the picture is inserted. To change a picture’s mask color, you have to delete the picture and add it again.
In the painter you can change the image size at any time by setting the Height and Width properties on each picture tab. All the pictures in the list are scaled to the specified size.
During execution, you can change the image size for a picture list only when that list is empty. The DeletePictures and DeleteStatePictures functions let you clear the lists.
This sample code illustrates how to change properties and add pictures to the regular picture list during execution. Use similar code for state pictures:
tv_list.DeletePictures()
tv_list.PictureHeight = 32
tv_list.PictureWidth = 32
tv_list.PictureMaskColor = RGB(255,255,255)
tv_list.AddPicture("c:\apps_pb\kelly.bmp")
tv_list.PictureMaskColor = RGB(255,0,0)
tv_list.AddPicture("Custom078!")
tv_list.PictureMaskColor = RGB(128,128,128)
tv_list.AddPicture("Custom044!")
Deleting pictures from the picture lists can have an unintended effect on item pictures being displayed. When you delete pictures, the remaining pictures in the list are shifted to remove gaps in the list. The remaining pictures get a different index value. This means items that use these indexes get new images.
Deleting pictures from the regular picture list also affects the overlay list, since the overlay list is not a separate list but points to the regular pictures.
To avoid unintentional changes to item pictures, it is best to avoid deleting pictures after you have begun using picture indexes for items.
