Dr. eX: Why does GetService(typeof(EnvDTE.DTE)) return null?

vsxteam — Mon, 09 Jun 2008 18:47:50 GMT

Ever build a Visual Studio package with code that looks like the following?

protected override void Initialize()

{

base.Initialize();

this.dte = GetService(typeof(DTE)) as DTE;

……

}

And then realize later on that this.dte is null?

A number of Visual Studio integrators have encountered just this problem in the past, and having recently seen this problem pop up again, it’s definitely past due for Dr. eX to blog about this.

The reason the above GetService call can sometimes return null, is due to the environment not being fully loaded and initialized. When the IDE is in this state it’s said to be in a “zombie” state. The IDE actually tracks this state with the VSPROPID_Zombie property.

To work around this problem, you simply need to defer the code in your Initialize method, until the VSPROPID_Zombie property has been set to false. To do this, your package should implement IVsShellPropertyChanges interface, and execute your initialization code from your IVsShellPropertyChanges.OnShellPropertyChange implementation. For example:

public class MyPackage : Package, IVsShellPropertyEvents

{

DTE dte;

uint cookie;

protected override void Initialize()

{

base.Initialize();

// set an eventlistener for shell property changes

IVsShell shellService = GetService(typeof(SVsShell)) as IVsShell;

if (shellService != null)

ErrorHandler.ThrowOnFailure(shellService.AdviseShellPropertyChanges(this,out cookie));

// code not depending on zombie state

……..

}

public int OnShellPropertyChange(int propid, object var)

{

// when zombie state changes to false, finish package initialization

if ((int)__VSSPROPID.VSSPROPID_Zombie == propid)

{

if ((bool)var == false)

{

// zombie state dependent code

this.dte = GetService(typeof(SDTE)) as DTE;

// eventlistener no longer needed

IVsShell shellService = GetService(typeof(SVsShell)) as IVsShell;

if (shellService != null)

ErrorHandler.ThrowOnFailure(shellService.UnadviseShellPropertyChanges(this.cookie));

this.cookie = 0;

}

return VSConstants.S_OK;

}

Happy coding,
Dr. eX

Dr. eX: How can I programmatically add a database connection to the server explorer toolwindow with my add-in?

vsxteam — Tue, 15 Jan 2008 13:10:00 GMT

For VS 2008, you can use the IVsDataExplorerConnectionManager.AddConnection method.

The easiest way to retrieve this interface is with the help of the Visual Studio SDK. You’ll need to install the VS SDK and add the following references to your add-in project.

Microsoft.VisualStudio.OLE.Interop.dll

Microsoft.VisualStudio.Shell.9.0.dll

Microsoft.VisualStudio.Data.dll

Microsoft.VisualStudio.Data.Core.dll

Microsoft.VisualStudio.Data.Framework.dll

Microsoft.VisualStudio.Data.Services.dll

Add the following using statements to your connect.cs file:

using Microsoft.VisualStudio.Shell;

using Microsoft.VisualStudio.Data.Core;

using Microsoft.VisualStudio.Data.Services;

using IOleServiceProvider = Microsoft.VisualStudio.OLE.Interop.IServiceProvider;

The you can retrieve and use the IVsDataExplorerConnectionManager.AddConnection method as follows:

// Quick test to connect to my SQL Server Northwind DB.

private void Test()

{

// Create a ServiceProvider object off the DTE object.

ServiceProvider sp = new ServiceProvider((IOleServiceProvider)_applicationObject);

// Retrieve the IVsDataExplorerConnectionManager service

IVsDataExplorerConnectionManager decMgr = (IVsDataExplorerConnectionManager)sp.GetService(typeof(IVsDataExplorerConnectionManager).GUID);

// This is the guid that identifies the SQL Server Provider (see HKLM\SOFTWARE\Microsoft\VisualStudio\9.0\DataProviders

Guid guidProvider = new Guid("91510608-8809-4020-8897-fba057e22d54");

// Add a connection node to the server explorer

decMgr.AddConnection("My Northwind DB", guidProvider, "Data Source=MyServer;Initial Catalog=Northwind;Integrated Security=True", false);

}

For those of you still using Visual Studio 2005, you’ll have to use an undocumented class called Microsoft.VisualStudio.Data.DataExplorerConnectionManager.

Again the easiest way to retrieve this class is to use the Visual Studio SDK (version 4 for VS 2005).

You’ll need to add the following references to your add-in project:

Microsoft.VisualStudio.Shell.dll

Microsoft.VisualStudio.OLE.Interop.dll

Microsoft.VisualStudio.Data.dll

The following using statements to your connect.cs file:

using Microsoft.VisualStudio.Shell;

using Microsoft.VisualStudio.Data;

using IOleServiceProvider = Microsoft.VisualStudio.OLE.Interop.IServiceProvider;

Then retrieve the DataExplorerConnctionManager and invoke it’s AddConnection method similar to the following:

private void Test()

{

// Create a ServiceProvider object from the DTE object

Microsoft.VisualStudio.Shell.ServiceProvider sp = new Microsoft.VisualStudio.Shell.ServiceProvider((IOleServiceProvider)_applicationObject);

// Retrieve the DataExplorerConnectionManager Service

DataExplorerConnectionManager dceMgr = (DataExplorerConnectionManager)sp.GetService(typeof(DataExplorerConnectionManager));

// This is the guid that identifies the SQL Server Provider (see HKLM\SOFTWARE\Microsoft\VisualStudio\8.0\DataProviders

Guid guidProvider = new Guid("91510608-8809-4020-8897-fba057e22d54");

// Add a connection node to the server explorer

dceMgr.AddConnection("My Northwind DB", guidProvider, "Data Source=MyServer;Initial Catalog=Northwind;Integrated Security=True", false);

}

Happy coding,
Dr. eX

VSX Team Blog : Dr. eX

Dr. eX: Why does GetService(typeof(EnvDTE.DTE)) return null?

Dr. eX: How can I programmatically add a database connection to the server explorer toolwindow with my add-in?