Developing SharePoint 2007 Webparts using Visual Studio 2010

So for the purposes of this article I am going create a basic visual web part, something that was difficult to do in SharePoint 2007 development. This process should work for most project types available…

1. Start New Project, select Visual Web Part
   
2. Select – Deploy as a farm solution
   
3. Write your custom web part. I have just created a simple web part that contains some text and a button. When the user clicks the button the button text will change.
   
4. I now press F5 on the keyboard and Visual Studio will automatically build & deploy my web part to SharePoint 2010.
5. I confirm it all works by adding the web part to the page. Great! But there is nothing special so far.
   
6. Now to get it into SharePoint 2007! First lets try deploying the current wsp as it is…
7. So we need to package up the solution.
   
8. Grab the wsp from the bin folder
9. Copy to SharePoint 2007 server.
10. Deploy to 2007 env and we get an error. The error tells us that it found a version number in the manifest that it doesnt understand.
    “Solution manifest for solution ’48cae4c9-68ba-cccf5a89304′ failed validation, file manifest.xml, line 2, character 110: The ‘SharePointProductVersion’ attribute is not declared.
    

Solution

After the steps above:

1. Go back into Visual Studio 2010.
2. Double click the “Package.package” file
3. Select “Manifest” down the bottom. Notice where is reads SharePointProductVersion=”14.0” in the xml file.
   
4. In the properties panel, clear out 14.0 in the SharePointProductVersion field. This removes the property all together from the manifest file.
   
5. We also need to change the assembly reference in the project from Microsoft.SharePoint.dll 14.0 to 12.0.
   To do this you will need to click the show all files icon in the solution explorer panel.    -Next, delete out Microsoft.SharePoint & delete out Microsoft.SharePoint.Security as these wont be on the SP 2007 environment.-Then you want to add a reference to Microsoft.SharePoint.dll but make sure its the 12.0 version found in C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\ISAPI\Microsoft.SharePoint.dll
6. Because we have built a ‘Visual Web Part’, Visual Studio 2010 automattically adds some imports into the ascx user control file which wont exists in SP 2007. Therefore you need to comment these references out. Obviously if we were doing a coded web part or a event receiver we would not need to do this step.Mine currently looks like this.
   
7. Package up your solution again and deploy on SP 2007 environment.
   
8. Active, test and your good to go.
   

Notes:

• You will need Asp.Net 3.5 installed on your SharePoint 2007 environment.
• This may not always be the right solution for you (depending on your project) but it certainly saves me a lot of time for those basic web parts.