How can I programmatically check-out an item for edit in TFS?

Some of the other approaches mentioned here only work for certain versions of TFS or make use of obsolete methods. If you are receiving a 404, the approach you are using is probably not compatible with your server version.

This approach works on 2005, 2008, and 2010. I don’t use TFS any longer, so I haven’t tested 2013.

var workspaceInfo = Workstation.Current.GetLocalWorkspaceInfo(fileName);
using (var server = new TfsTeamProjectCollection(workspaceInfo.ServerUri))
{
    var workspace = workspaceInfo.GetWorkspace(server);    
    workspace.PendEdit(fileName);
}