The
File Controls: Three of the controls on the Toolbox let
you access the computer’s file system. They are the DriveListBox, DirListBox,
and FileListBox controls. Using these controls, the user can traverse the host
computer’s file system, locate any folders or files on any hard disk, even on
network drives.
Three File controls are used in the design of Forms that let users explore the entire structure of their hard disks.
• DriveListBox
Displays the names of the drives within and connected to the PC. The basic
property of this control is the Drive property, which sets the drive to
be initially selected in the control or returns the user’s selection.
• DirListBox
Displays the folders of the current drive. The basic property of this control
is the Path property, which is the name of the folder whose subfolders
are displayed in the control.
• FileListBox
Displays the files of the current folder. The basic property of this control is
also called Path, and it’s the path name of the folder whose files are
displayed.
The three File
controls aren’t tied to one another. To connect the File controls, you must
assign the appropriate values to their basic properties. To force the
DirListBox to display the folders of the selected drive in the DriveListBox,
you must make sure that each time the user selects another drive, the Path
property of the DirListBox control matches the Drive property of the
DriveListBox. The following is the minimum code you must place in the
DriveListBox control’s Change event:
Private Sub Drive1_Change()
Dir1.Path = Drive1.Drive
End Sub
Similarly, every
time the current selection in the DirListBox control changes, you must set the
FileListBox control’s Path property to point to the new path of the DirListBox
control:
Private Sub Dir1_Change()
File1.Path = Dir1.Path
End Sub
you’ll
want to limit the files displayed in the FileListBox. To do this, use the
control’s Pattern property, which lets you specify which files will be
displayed with a file-matching string such as “*.TXT” or “1997*.XLS”.
File1.Pattern = Combo1.Text
