The Shell Document Object and Control Library


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This article describes the "Shell Doc Object and Control Library" ("SHDocVw.dll"). The library contains the user interface (documents) portions of both Internet Explorer and the file system. In this context, the file system is the Windows Explorer accessory that you use to look at Windows folders and files. The "SHDocVw.dll" library is a COM object, it is not managed.

The executable file for Internet Explorer is IExplore.exe. It uses "SHDocVw.dll" which uses Mshtml.dll and other Active Document components. Mshtml.dll is the library for HTML. The "SHDocVw.dll" library is also known as the WebBrowser Control, however it is the COM (unmanaged) version. The .Net (managed) WebBrowser Control is a wrapper of the COM version.

For Internet Explorer, the two most common uses of the library are:

  • Enumerate the open Internet Explorer browser windows
  • Create a new instance of an Internet Explorer browser window outside of our program

The open Internet Explorer browser windows can be enumerated using the ShellWindows member. The items in the collection are InternetExplorer objects. Most InternetExplorer objects are Internet Explorer browser windows but some InternetExplorer objects are "Windows Explorer" (the application for looking at files and folders) windows.

The InternetExplorer object can also be used to open a new instance of an Internet Explorer browser window. We shall try doing that first. Before we do, we must add a reference to "SHDocVw.dll". I will assume you know how to create projects in Visual Studio and how to add references. Create a project or use an existing project. In the "Reference Manager" window go to the "COM" libraries as in the following:

Reference Manager

Then click on the "Browse" button and browse to your "\Windows\System32" folder and select "SHDocVw.dll" as in the following:

sys32 folder

Be sure to place a checkmark next to the library, then click on "OK".

Next use the following code to create an Internet Explorer browser window:

SHDocVw.InternetExplorer ie = new SHDocVw.InternetExplorer();
ie.Visible = true;
ie.Navigate("http://microsoft.com");

The open Internet Explorer browser windows can be enumerated as easily as:

SHDocVw.ShellWindows ShellWindows = new SHDocVw.ShellWindows();
foreach (Object o in ShellWindows)
{
	SHDocVw.InternetExplorer ie = o as SHDocVw.InternetExplorer;
	if (ie != null)
	{
		try
		{
		if (ie.Document.GetType().Name == "HTMLDocumentClass")
			// it is an Internet Explorer browser window
		}
		catch (Exception ex)
		{
			// handle error
		}
	}
}

Note that if you have web sites in multiple tabs within an Internet Explorer window then each tab will be a separate InternetExplorer object.

When enumerating or creating new browser windows this way, it is possible to control them, at least somewhat. We will explore what we can do in future articles.

References

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