Advanced Windows Forms

The topic of “Data binding” is taken up in chapter 17. This discusses complex data binding by way of the DataGrid control, and simple binding of data to Windows Forms controls in general. This chapter will illustrate how to provide transactional updates within a class and automatically invoke these updates from a bound control. A new MyAlbumData application is constructed over the course of this chapter.

Chapter 18 is called “Odds and ends .NET,” and completes our discussion with a review of various topics that should be of further interest. These include printing, Windows Forms timers, drag and drop, and ActiveX controls. An example for each topic is provided using the MyPhotos MDI application built in chapter 16.

Following this last chapter are four appendices with some additional information on C#, an overview of .NET namespaces, a class hierarchy chart of the Windows Forms namespace, and resources for additional information on C# and the .NET Framework.

List views

To kick off the advanced section of the book, we take a detailed look at the ListView class. This class is used by applications such as Windows Explorer to present a collection of items in list form. We will examine this class in detail, including the following topics:

•Various styles supported by the ListView class.

•Members of the ListView class.

•Defining list view columns in Visual Studio and programmatically.

•Selecting and editing items in the list.

•Activating list view items.

•Dynamically switching the contents of a list view.

We will start from scratch here and build a new application called MyAlbumExplorer. In this chapter we will display both albums and photographs in the main window. The next chapter will add support for a TreeView control to this application to create a window much like the Windows Explorer application utilizes for file system objects.

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14.1THE NATURE OF LIST VIEWS

In many ways, a list view is a more glamorous version of a list box. Other than the fact that they are both controls, there is no relation from a class hierarchy perspective, but conceptually both present a scrollable list to the user. The ListBox class stores a collection of object instances, while the ListView class contains a collection of ListViewItem instances, which in turn contains a collection of ListViewSubItem objects.

Another difference is how their contents are displayed. The ListBox control displays a string associated with each object by default, and supports an owner-drawn style to display other formats. The ListView control displays its items in one of four views represented by the View enumeration, as described by .NET Table 14.1. When the Details view is displayed, the collection of subitems appears in a configured set of ColumnHeader objects associated with the control.

.NET Table 14.1 View enumeration

The View enumeration specifies the different ways the contents of a ListView control can appear. This enumeration is part of the System.Windows.Forms namespace. The following table provides an example obtained from the Windows Explorer application.

LargeIcon Each item appears as a large icon with a label below it. By default, items can be dragged around and placed at any location within the control.

.NET Table 14.1 View enumeration

Figure 14.1 shows a Form with a ListView control displayed in the Details view mode. This figure illustrates various features and classes used by this control. We will look at these in detail as we progress through the chapter.

.NET Table 14.2 ListView class

The ListView class is a control that displays a collection of labeled items as a list in one of four different views. Typically an icon is displayed for each item in the collection to provide a graphical indication of the nature or purpose of the item. Items can be displayed with large icons, small icons, in a list format, or in a detailed list format. The detailed list permits additional information about each item to appear in columns within the control. This class is part of the System.Windows.Forms namespace, and inherits from the Control class. See .NET Table 4.1 on page 104 for a list of members inherited by this class.