Freetutes.com

VB6 beginners tutorial - Learn VB6

Advanced VB6 tutorial - Learn Advanced VB6

VB .NET - Learn Visual Basic .NET

Systems Analysis - System analysis and Design tutorial for Software Engineering


You are here: Visual Basic > Advanced VB6 tutorial > Chapter 4

ListItem Object and ListItems Collection of ListView Control - Visual Basic 6

Each item in the ListView is called a ListItem object. If you look at Figure 4.6, for example, you will see a list of files in the Visual Basic directory. Biblio.mdb, Readme.hlp, and each of the other files in the right side of the Windows Explorer is a ListItem.

The ListView control organizes all the ListItem objects into a single collection called ListItems. This is similar to a TreeView, which organizes each Node object in a tree into the Nodes Collection. The ListItems Collection can be used to cycle through all the objects in the control for processing, just as with any other collection (see Listing 4.2).

LISTING 4.2

PROCESSING THE ITEMS CONTAINED IN A LISTVIEW CONTROL

Dim objItem as ListItem
For Each objItem in ListView1.ListItems
' do some processing÷
Next

Index and Key Properties

You can refer to Items in a ListView by either the Index property or the Key property. The Index property is an integer expression typically generated by Visual Basic when a ListItem is added to the ListView. You can refer to a specific item by number:

Msgbox ListView1.ListItems(1).Text

Alternatively you can loop through the collection of ListItems, referring to each by number, as illustrated in Listing 4.3.

LISTING 4.3

LOOPING THROUGH A LISTVIEW CONTROL'S LISTITEMS BY NUMBER

For I = 1 To ListView1.ListItems.Count
Msgbox ListView1.ListItems(I).Text
Next I

Unlike the Index in the TreeView, you have some control over the value of the Index property in the ListView control. Specifying an Index number is discussed later in this section.

A more convenient way to reference an item in the list is by Key. The Key property is a string expression—assigned by you as the developer (or by the user if you desire)—that can also be used to access an item in the list. The Key property is included as part of the Add method (discussed later) when an item is inserted into the list.

As a developer you usually know the value for the Key and can access a node directly. It is easier to refer to the node you want by using a meaningful text string than by using the Index property that is determined by Visual Basic.

Unlike the TreeView you can store numbers in the Key property of each ListItem if necessary. You just have to convert the number to a string by using the Str$() function, and the string value will be accepted as the Key by Visual Basic.

ListView Control topics

See Also


  

.<< Previous | Contents | Next >>

Home | About Us | Privacy Policy | Contact Us

Copyright © Freetutes.com | All Rights Reserved