Tip 206: Populating the Outline Control with a List of Directories and Files Stored on a Disk

February 28, 1996

Abstract

The Microsoft® Windows® File Manager and Explorer applications use an Outline control to display directories and files in a hierarchical list. This article explains how to populate the Microsoft Visual Basic® version 4.0 Outline control using this same technique.

Using the Outline Control

The Microsoft® Visual Basic® version 4.0 Outline control is an advanced List Box control that allows you to display a hierarchical list of items to your user. The Outline control allows you to present items with indentation levels that can be expanded (the subordinate items become visible) or collapsed (the subordinate items become invisible). This means that a directory can be saved to the Outline control at one level of indentation and the files stored within that directory can be stored at a secondary level of indentation.

The example program below populates an Outline control with all directories and files stored on the selected disk. This feat is accomplished by performing a recursive search through the disk's file structure. The name of a file is retrieved from the disk's directory. If this entry is a directory, it is added to the Outline control as a first-level indentation item. However, if the entry is a file, the entry is added to the Outline control at the next level of indentation. This action is repeated until every directory and file has been processed.

Example Program

This program shows how to populate the Outline control with all directory and files stored on a disk drive.

1. Create a new project in Visual Basic. Form1 is created by default.
   
   
2. Add the following code to the General Declarations section of Form1:

   Option Explicit
   Dim FIndent As Integer
   Dim FIndex As Integer
   Dim StrtPath As String
   

3. Add an Outline control to Form1. Outline1 is created by default.
   
   
4. Add a Drive List Box control to Form1. Drive1 is created by default.
   
   
5. Add the following code to the Change event for Drive1:

   Private Sub Drive1_Change()
       Outline1.Clear
       Outline1.AddItem Drive1.Drive & "\"
       FIndent = 1
       FIndex = 0
       StrtPath = Drive1.Drive
       Get_Files StrtPath
       MsgBox "OK"
   End Sub
   

6. Create a new procedure called Get_Files. Add the following code to this procedure:

   Private Sub Get_Files(FPath As String)
       Dim File_Name As String
       Dim File_Path As String
       Dim File_Read As Integer
       Dim X As Boolean
       Dim I As Integer
   
       FIndent = FIndent + 1
       File_Path = FPath & "\"
       File_Name = Dir$(File_Path, vbDirectory)
       File_Read = 1
       X = False
   
       Do While File_Name <> ""
           If File_Name <> "." And File_Name <> ".." Then
               If GetAttr(File_Path & File_Name) <> vbDirectory Then
                   Outline1.AddItem File_Name
                   FIndex = FIndex + 1
                   Outline1.Indent(FIndex) = FIndent
               Else
                   StrtPath = File_Path & File_Name
                   Outline1.AddItem File_Name
                   FIndex = FIndex + 1
                   Outline1.Indent(FIndex) = FIndent
                   X = True
                   Get_Files StrtPath
               End If
           End If
           If X = True Then
               File_Name = Dir$(File_Path, vbDirectory)
                   For I = 2 To File_Read
                       File_Name = Dir$
                   Next
               X = False
           End If
           File_Name = Dir$
           File_Read = File_Read + 1
       Loop
       FIndent = FIndent - 1
   End Sub
   

Run the example program by pressing  Select a disk drive from the Drive List Box control by clicking the desired drive letter. The program will display a message box when it has populated the Outline control with all directories and files found on the target disk drive.

Additional References

Knowledge Base Q118939. "How to Add Highlight Ability to Visual Basic's Outline Control."

"List Box Controls." (MSDN Library, Technical Articles)

"Tip 15: Creating a List of Directories Stored on a Disk."

"Tip 123: Displaying Records from a Microsoft Access Database in an Outline Control."

"Tip 124: Determining Available Disk Drives in Visual Basic."