ADD EVENT HANDLERS FOR THE VIEW MENU (continued)

Your program will work just fine here. It doesn’t do very much, but it does work. Our final step for this section is to populate the list control with the available albums.

14.2.3Populating a ListView

Our final task here is to populate the ListView control. As we said earlier in the chapter, a ListView control contains a collection of ListViewItem objects. As indicated in .NET Table 14.3, the ListViewItem object inherits directly from the Sys-

tem.Object class. All of the painting and other management of list items are performed by the ListView class itself. This painting behavior is consistent with other container controls we have seen such as the StatusBar control containing StatusBarPanel objects, and the ListBox control containing a set of object instances.

Our use of the ListViewItem object here will be fairly modest. We will get more complicated later in the chapter. For now, we simply wish to create an item for each album with the file name as the label and an appropriate image icon assigned. This requires that we create an ImageList for both the small and large icons to display in the view, and populate the Items property for the list with a ListViewItem for each album.

.NET Table 14.3 ListViewItem class

The ListViewItem class is an object that can be displayed within a ListView control. It is part of the System.Windows.Forms namespace, and supports the IClonable and ISerializable interfaces.

We will begin with the ImageList components.

CREATE THE IMAGE LISTS FOR THE VIEW

The code generated by these changes is similar to examples we have seen before. The images are stored in a .resx file for the MainForm object, and loaded into the application using the ResourceManager class.

Now that we have the image lists defined, the form containing a ListView control, and the View menu primed and ready, we have nothing to do but add our photo albums to the list. We do this in the OnLoad method, which is called just before the Form displays the first time. We could instead add these items in the MainForm constructor, but the OnLoad method is preferred for such actions to ensure that the Form is fully initialized.

Let’s see how this code looks.

ADD EACH ALBUM TO THE VIEW

ADD EACH ALBUM TO THE VIEW (continued)

This creates a list item for each album found, using the base file name as the text for the album. If an album fails to open, then an error image is assigned as its icon. If any of your albums happen to have a nonempty password set, then the PhotoAlbum class will prompt you for this password before opening the album.

As you progress through this chapter, you will note that the album password is required repeatedly as the album is opened, which is not of course the nicest interface one could ask for. We could fix this by only requiring the password in the

Album class when the user wants to examine the photos or modify the album We will not actually do this, but we could.

Compile and run this program to see our new list view at work. Also alter the display setting using the items in the View menu. Assuming you have some album files in the album directory, you should find that the Large Icons, Small Icons, and List menus work just fine. Curiously, the Details setting displays nothing at all.

This is because the Details view requires a set of columns to be assigned to the form. So far we have not done this, so we will make it our next topic.