Problem
Encountering an error when trying to instantiate COM objects through Primarary Interop Assemblies (PIA’s) or Runtime Callable Wrappers (RCW’s) created using the TLBIMP.exe tool.
When calling the object for the first time, you encounter the following COM exception:
Unable to cast COM object of type ‘xxx to interface type ‘xxx’. This operation failed because the QueryInterface call on the COM component for the interface with IID ‘{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}’ failed due to the following error: No such interface supported (Exception from HRESULT: 0×80004002 (E_NOINTERFACE)).
You are likely to encounter this problem when developing ASP.Net applications, Windows Console applications, or Windows Services. You are unlikely to experience this issue when developing Windows Forms applications.
Solution
The problem is that you are attempting to call Single-Threaded Apartment (STA) model COM components from an Multi-Threaded Apartment (MTA) thread. The primary thread of Windows Forms applications are STA threads, so the components work fine there. Most other project types, including Console applications and Windows Service applications are run on an MTA thread by default. When you attempt to instantiate the an STA component, you will get the ubiquitous error described above.
You might try calling System.Threading.Thread.CurrentThread.SetApartmentState(ApartmentState.STA), but this won’t work. You cannot change the thread execution model on a running thread.
To fix the problem, you can set the thread execution type on the main application thread before it is started, but this is not optimal. It is better to set the threading model specifically for the portion of code that needs it.
A better solution is to spin up a new thread for the job at hand, and set the thread execution state on the new thread before executing it. There are a few different methods to accomplish this depending on what you’re trying to accomplish. Here’s one to get you started:
using System.Threading;
...
// Setup an object to host the thread entry point
// Start a process on an MTA thread
MyThreadedJob jobHost = new MyThreadedJob(jobId);
Thread t = new Thread(new ThreadStart(MyThreadedJob.Execute));
t.SetApartmentState(ApartmentState.MTA);
// Start the thread
t.Start();
// Wait for thread to complete (optional)
t.Join();
More Gory Details
For more of the gory details and differences between threading models in Windows and COM, you can start here.
Categories: .Net · C# · COM Interop · Threading
I want to get a reference to a SPList object associated with a given list url. This method works with any of the url’s associated with the list, including view page url’s, or list form url’s.
This should be much easier to achieve by using the object model, in my opinion. String parsing of the url is not my favorite, but I couldn’t find a better way to accomplish it.
If you know of an easier way to accomplish this, please leave me a comment. Otherwise, you can steal this from me, if you want it!
/// <summary>
/// Gets an SPList based on the url to the list
/// </summary>
/// <param name="listUrl">Full url to the list</param>
/// <returns>SPList object, null if list is not found</returns>
public SPList GetListByUrl(string listUrl)
{
SPList list = null;
try
{
using (SPSite site = new SPSite(listUrl))
{
if (site != null)
{
// Strip off the site url, leaving the rest
// We'll use this to open the web
string webUrl = listUrl.Substring(site.Url.Length);
// Strip off anything after /forms/
int formsPos = webUrl.IndexOf("/forms/", 0, StringComparison.InvariantCultureIgnoreCase);
if (formsPos >= 0)
{
webUrl = webUrl.Substring(0, webUrl.LastIndexOf('/', formsPos));
}
// Strip off anything after /lists/
int listPos = webUrl.IndexOf("/lists/", 0, StringComparison.InvariantCultureIgnoreCase);
if (listPos >= 0)
{
// Must be a custom list
// Strip off anything after /lists/
webUrl = webUrl.Substring(0, webUrl.LastIndexOf('/', listPos));
}
else
{
// No lists, must be a document library.
// Strip off the document library name
webUrl = webUrl.Substring(0, webUrl.LastIndexOf('/'));
}
// Get the web site
using (SPWeb web = site.OpenWeb(webUrl))
{
if (web != null)
{
// Initialize the web (avoids COM exceptions)
string title = web.Title;
// Strip off the relative list Url
// Form the full path to the list
//string relativeListUrl = listUrl.Substring(web.Url.Length);
//string url = SPUrlUtility.CombineUrl(web.Url, relativeListUrl);
// Get the list
list = web.GetList(listUrl);
}
}
}
}
}
catch { }
return list;
}
Enjoy!
Categories: .Net · C# · MOSS 2007 · SharePoint
I want to thank everyone who attended my session on SharePoint Workflow with Visual Studio at our TechFest event yesterday. Please feel free to post any comments (good or bad) about my presentation or the event.
Demo source code is posted on Nakido until the Techfest site is updated with session content.
SharePoint WorkFlow with Visual Studio – Downloads
SharePoint WorkFlow with Visual Studio – References
Categories: .Net · C# · MOSS 2007 · Microsoft Office · SharePoint · Visual Studio · WSS 3.0 · Workflow
Problem
SharePoint 2007 Web Front End (WFE) servers crashing repeatedly. Environment is SharePoint 2007 (MOSS Enterprise) 64-bit running on Windows Server 2008 Standard. Server was crashing repeatedly with CPU spiking to 100%, blue screen, and server rebooting itself. System log showing BugCheck event (1000) entry with code 0×0000001d:
The computer has rebooted from a bugcheck. The bugcheck was: 0×000000d1 (0xfffff9802ea0ef50, 0×0000000000000002, 0×0000000000000000, 0xfffffa6004e06ed9). A dump was saved in: C:\Windows\MEMORY.DMP.
Resolution
After a lot of troubleshooting, it turns out it was Trend Micro Common Firewall Driver (Trend Micro OfficeScan Client 8.0). When we disabled the firewall, problem resolved.
Categories: MOSS 2007 · SharePoint · WSS 3.0 · Windows Server 2008
Problem:
I’m creating a SharePoint Sequential Workflow using Visual Studio 2008 (SP1) with .Net 3.5 SP1 installed. This is on a Windows 2003 R2 VPC with SharePoint 2007 (MOSS Enterprise) installed on the local machine for development. A Collaboration Portal is installed on a web site with host headers (portal) assigned to port 80.
When I create a new workflow project, the wizard asks for a path to the SharePoint site. I type in my url (http://portal in my case), and the project wizard fails, saying “SharePoint server not installed. Please run Microsoft Office SharePoint Server 2007 setup.“
I’m logged in as the farm administrator. I thought it might be a permissions issue (my farm admin doesn’t have full rights on the domain), so I went back and gave it full Domain Admin rights in case that was the problem. Still failing!!
What the hell?
Resolution:
It turns out that the wizard does some funny business behind the scenes, calling the database directly. When I give my development account (farm admin) account full rights (dbo) to the SharePoint content database for my portal site, bingo! Works like a champ.
After only an hour or two spinning my wheels. Sigh….
Categories: .Net · C# · MOSS 2007 · SharePoint · Visual Studio · Workflow
Building a SharePoint 2007 workflow using WSPBuilder and Visual Studio 2008. Love, love, love the WSPBuilder tool, but the workflow templates could use some work. Ran into this one today…
Problem
I was receiving “Failed on Start (retrying)” errors. SharePoint logs showed “The workflow failed validation” exceptions. This usually means a problem with the .rules files associated with a Declarative Rule Condition.
I changed my While activities to use code conditions instead, and the problem went away. But I really wanted to find the source of the issue. After much trial and error and fruitless searches on the web, I finally found it. Turns out, it was a missing import target declaration in the .csproj file created by WSPBuilder when I created a workflow project using the “WSPBuilder Workflow with Workflow” project template.
Resolution
To fix the problem, opened up the project file and added the missing import target line (in green), below. Evidently, this line tells studio to include the .rules in the assembly.
<Import Project=”$(MSBuildBinPath)\Microsoft.CSharp.targets” />
<Import Project=”$(MSBuildExtensionsPath)\Microsoft\Windows Workflow Foundation\v3.5\Workflow.Targets” />
Reopened the project, recompile, build wsp, redeploy. Bingo! Now my workflow works with Declarative Rule Conditions, as it should!
Credits
Thanks to Greg G’s post here that pointed me in the right direction.
Categories: SharePoint · Visual Studio · WSPBuilder · Workflow
Ok, this is painfully easy. Setup a Network Place in Windows Explorer, browse to the web site or folder in question, right-click -> Properties.
Duh!! Sometimes the solution is literally staring you in the face! Thanks to Kelly Ballard for pointing this one out.
Categories: SharePoint
The hardest part about this (by far) is figuring out how to publish the page after you’ve made your changes. Every time I need to do it, I have to dig up some old code.
Thought I’d blog it this time, to make it easier on myself next time around.
using Microsoft.SharePoint;
using Microsoft.SharePoint.Publishing;
...
using (SPSite site = new SPSite("http://portal"))
{
SPWeb web = site.RootWeb;
// Check to ensure the web has publishing turned on
if (!PublishingWeb.IsPublishingWeb(web))
{
throw new ApplicationException("Web does not have publishing enabled");
}
// Get a reference to the publishing web and publishing site
PublishingWeb pubWeb = PublishingWeb.GetPublishingWeb(web);
PublishingSite pubSite = new PublishingSite(web.Site);
// Get page layout from the page layouts collection
PageLayoutCollection siteLayouts = pubSite.GetPageLayouts(false);
PageLayout myLayout = siteLayouts["/_catalogs/masterpage/MyLayout.aspx"];
// Get a reference to a publishing page
PublishingPageCollection pages = pubWeb.GetPublishingPages();
PublishingPage page = pages["pages/default.aspx"];
// Check out the list item as needed
bool forceCheckout = page.ListItem.ParentList.ForceCheckout;
if (forceCheckout)
{
// Is the page checked out?
if (page.ListItem.File.CheckedOutBy != null)
{
// Throw an exception if the page is checked out
string pageCheckedOut = string.Format("Page {0} is checked out by {1}", page.Url, page.ListItem.File.CheckedOutBy);
throw new SPException(pageCheckedOut);
}
// Check out the page
page.CheckOut();
}
// Change the page layout
page.Layout= myLayout;
// Update the page and check in changes
page.Update();
// Publish the page
// This handles the page checkin and publishing the draft
ApprovePublishingPage(page, "Modified page layout");
}
/// <summary>
/// Approves changes to a publishing page
/// </summary>
/// <param name="page">PublishingPage with changes to be published</param>
/// <param name="comment">Comment associated with the change</param>
public void ApprovePublishingPage(PublishingPage page, string comment)
{
// Check in the page if required
SPFile pageFile = page.ListItem.File;
if (pageFile.Level == SPFileLevel.Checkout)
{
pageFile.CheckIn(comment, SPCheckinType.MajorCheckIn);
}
// Skip these steps if the parent list doesn't support moderation
if (page.ListItem.ParentList.EnableModeration)
{
// If page is in "pending" status, approve it
SPModerationInformation modInfo = page.ListItem.ModerationInformation;
if (modInfo.Status == SPModerationStatusType.Pending)
{
pageFile.Approve(comment);
}
// If page is in draft status, publish it
if (modInfo.Status == SPModerationStatusType.Draft)
{
pageFile.Publish(comment);
}
}
}
Enjoy!
Categories: C# · MOSS 2007 · SharePoint
I build lots of VPC’s for demos, labs, prototypes, etc. With the various flavors of Windows out there, I find it hard to find the Windows Activation icon to verify activation.
I found a new tip today to fire Windows Activation from the command line. This technique works on Windows XP and Windows Server 2003, but does not work on Windows Vista or Windows Server 2008.
No more searching to find the Windows Activation icon!
- Click Start > Run
- Type “oobe/msoobe /a”
- This command triggers the “Out Of Box Experience” activation application, which opens the Windows activation screen.
- If Windows is already activated, it will tell you so, otherwise, you can continue to activate Windows.
Thanks to command-tab.com for this useful tip! For more info, see How To Activate Windows XP in 5 Minutes or Less.
Categories: Windows Server 2003 · Windows XP
After installing Windows Server 2008, I found I can’t ping the server, even within a “Private Network”. I like to ping stuff in my spare time, so this was distressing to me. I suspected to find a firewall issue, but was surprised to find enabling the Network Discovery option in the firewall configuration settings didn’t fix it.
Configure Windows Firewall Settings – File and Printer Sharing
By default, Windows Firewall for WIndows Server 2008 is configured to disallow File and Printer Sharing on the network. By default Windows Server 2008 firewall is configured with Windows Firewall running, and with File and Printer Sharing disabled. This blocks ICMP Echo Request packets used by the PING command. You can allow the server to respond to ping requests by doing the following:
- Turn off Windows Firewall on the Windows 2008 Server (not recommended)- OR -
- Enable the File and Printer Sharing option in Windows Firewall Configuration Settings
- Start > Control Panel > Network and Intranet
- Under the Windows Firewall section heading, Click the Allow a program through Windows Firewall link
- In the programs and ports list, check the File and Printer Sharing option
Categories: Windows Server 2008
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