How to modify the Site Settings page programmatically?

Question

I need to modify the Site Settings page in a site collection to include an extra link. How can I go about doing this using c#?

Answer 1

You need to deploy a custom action in a feature that looks like this:

<Elements xmlns="http://schemas.microsoft.com/sharepoint/"> 
  <CustomAction 
     Id="YourLinkId" 
     GroupId="SiteCollectionAdmin" 
     Location="Microsoft.SharePoint.SiteSettings" 
     RequireSiteAdministrator="true" 
     Sequence="30" 
     Title="Display text for your link"> 
    <UrlAction Url="link to your page" /> 
  </CustomAction> 
</Elements>

Read Custom Action Schema for GroupId and Location values.

Answer 2

No need for C# code, it can be done declaratively with custom actions through a feature.

Check details on MSDN.