The Microsoft Windows Shell provides a powerful set of automation objects that enable you to program the Shell with Microsoft Visual Basic and scripting languages such as Microsoft JScript (compatible with ECMA 262 language specification) and Visual Basic Scripting Edition (VBScript). You can use these objects to access many of the Shell's features and dialog boxes. For example, you can access the file system, launch programs, and change system settings.
This section introduces the scriptable Shell objects.
Shell Versions
Many of the Shell objects became available in version 4.71 of the Shell. Others are available in version 5.00 and later. This means that on computers running Windows 95 or Microsoft Windows NT 4.0, the Shell objects are available only if the integrated desktop is installed. Version 4.71 of the Shell is on all Windows 98 computers, and version 5.00 is on all Windows 2000 computers. The following table lists each Shell object under the version of the Shell in which the object became available.
Instantiating Shell Objects
To instantiate the Shell objects in Visual Basic applications with early binding, add references to the following libraries in your project:
- Microsoft Internet Controls (SHDocVw)
- Microsoft Shell Controls and Automation (Shell32)
Late Binding
You can also instantiate many of the Shell objects with late binding. This approach works in Visual Basic applications and in script. The following example shows how to instantiate the Shell object in JScript.
<SCRIPT LANGUAGE="JScript">
<!--
function fnCreateShell()
{
// Instantiate the Shell object and invoke its FileRun method.
var oShell = new ActiveXObject("Shell.Application");
oShell.FileRun;
}
-->
</SCRIPT>
The following example shows how to instantiate the Folder object in VBScript.
<SCRIPT LANGUAGE="VBScript">
<!--
function fnCreateFolder()
dim oShell
dim oFolder
dim sDir
sDir = "C:\SomePath"
set oShell = CreateObject("Shell.Application")
set oFolder = oShell.NameSpace(sDir)
end function
-->
</SCRIPT>
In the preceding example, sDir is the path to the Folder object. Note that the ShellSpecialFolderConstants enumeration values are not available in script.
The ProgID for each of the Shell objects is shown in the following table.
HTML OBJECT Element
You can also use the OBJECT element to instantiate Shell objects on an HTML page. To do this, set the OBJECT element's ID attribute to the variable name you will use in your scripts, and identify the object using its registered number (CLASSID). The following HTML creates an instance of the ShellFolderItem object using the OBJECT element.
<OBJECT ID="oShFolderItem"
NAME="Shell Folder Item Object"
CLASSID="clsid:2fe352ea-fd1f-11d2-b1f4-00c04f8eeb3e">
</OBJECT>
The following table lists each Shell object and its respective CLASSID.
Shell Object
The Shell object represents the objects in the Windows Shell. You can use the methods exposed by the Shell object to:
- Open, explore, and browse for folders.
- Minimize, restore, cascade, or tile open windows.
- Launch Control Panel applications.
- Display system dialog boxes.
Users are perhaps most familiar with the commands they access from the Start menu and the taskbar's shortcut menu. The taskbar's shortcut menu appears when users right-click the taskbar. The following HTML Application (HTA) produces a start page with buttons that implement many of the Shell object's methods. Some of these methods implement features on the Start menu and the taskbar's shortcut menu.
<HTML>
<HEAD>
<TITLE>Start Page</TITLE>
<OBJECT ID="oShell"
CLASSID="clsid:13709620-C279-11CE-A49E-444553540000">
</OBJECT>
<STYLE>
INPUT {width: 200}
</STYLE>
<SCRIPT LANGUAGE="VBScript">
<!--
function fnStart(sMethod)
select case sMethod
case 0
'Minimizes all windows on the desktop
oShell.MinimizeAll
case 1
'Displays the Run dialog box
oShell.FileRun
case 2
'Displays the Shut Down Windows dialog box
oShell.ShutdownWindows
case 3
'Displays the Find dialog box
oShell.FindFiles
case 4
'Displays the Date/Time dialog box
oShell.SetTime
case 5
'Displays the Internet Properties dialog box
oShell.ControlPanelItem "INETCPL.cpl"
case 6
'Explores the My Documents folder
oShell.Explore "C:\My Documents"
case 7
'Enables user to select folder from Program Files
oShell.BrowseForFolder 0, "My Programs", 0, "C:\Program Files"
case 8
'Opens the Favorites folder
oShell.Open "C:\WINDOWS\Favorites"
case 9
'Displays the Taskbar Properties dialog box
oShell.TrayProperties
end select
end function
-->
</SCRIPT>
</HEAD>
<BODY>
<H1>Start...</H1>
<INPUT type="button" value="Edit Taskbar Properties" onclick="fnStart(9)"><br>
<INPUT type="button" value="Open Favorites Folder" onclick="fnStart(8)"><br>
<INPUT type="button" value="Browse Program Files" onclick="fnStart(7)"><br>
<INPUT type="button" value="Explore My Documents" onclick="fnStart(6)"><br>
<INPUT type="button" value="Modify Internet Properties" onclick="fnStart(5)"><br>
<INPUT type="button" value="Set System Time" onclick="fnStart(4)"><br>
<INPUT type="button" value="Find a File or Folder" onclick="fnStart(3)"><br>
<INPUT type="button" value="Shut Down Windows" onclick="fnStart(2)"><br>
<INPUT type="button" value="Run" onclick="fnStart(1)">
<INPUT type="button" value="Minimize All Windows" onclick="fnStart(0)">
</BODY>
</HTML>
Security
As an application, an HTA runs under a different security model than a Web page. To interact with a Web page that implements the functionality of the Shell objects, users must enable the Initialize and script ActiveX Controls not marked as safe option for the security zone in which they are viewing the page.
Folder Objects
The Folder object represents a Shell folder. You can use the methods exposed by the Folder object to:
- Get information about a folder.
- Create subfolders.
- Copy and move file objects into the folder.
The FolderItem object represents an item in a Shell folder. Its properties enable you to retrieve information about the item. You can use the methods exposed by this object to run an item's verbs, or to retrieve information about an item's FolderItemVerbs object.
The FolderItems object represents a collection of items in a Shell folder. Its methods and properties enable you to retrieve information about the collection.
The following Visual Basic example shows the relationship between several of the folder objects and how they can be used together. When the user clicks the command button called cmdGetPath, the program displays a dialog box that enables the user to select a folder from My Computer, where ssfDRIVES is the ShellSpecialFolderConstants enumeration value for My Computer. When the user chooses a folder, the folder's path is displayed in the text box called txtPath.
Private Sub cmdGetPath_Click()
Dim oShell As New Shell
Dim oFolder As Folder
Dim oFolderItem As FolderItem
Set oFolder = oShell.BrowseForFolder(Me.hWnd, "Select a Folder", 0, ssfDrives)
Set oFolderItem = oFolderItems.Item
txtPath.Text = oFolderItem.Path
End Sub
In VBScript, this function is slightly different because the ShellSpecialFolderConstants enumeration values are not available in script. The following example shows the VBScript equivalent of the previous example.
<SCRIPT LANGUAGE="VBScript">
<!--
function fnGetMyPathVB()
dim oShell
dim oFolder
dim oFolderItem
set oShell = CreateObject("Shell.Application")
set oFolder = oShell.BrowseForFolder(0, "Choose a Folder", 0)
set oFolderItem = oFolder.Items.Item
document.all.item("myPath").innerText = oFolderItem.Path
end function
-->
</SCRIPT>
In the following JScript example, which is a direct translation of the preceding VBScript example, note how the empty parentheses '()' are used to invoke the Items and Item methods.
<SCRIPT LANGUAGE="JavaScript">
<!--
function fnGetMyPathJ()
{
var oShell = new ActiveXObject("Shell.Application");
var oFolder = new Object;
oFolder = oShell.BrowseForFolder(0, "Choose a folder", 0);
var oFolderItem = new Object;
oFolderItem = oFolder.Items().Item();
document.all.item("myPath").innerText = oFolderItem.Path;
}
-->
</SCRIPT>