TFS / File Checkout from C#

You can use PendEdit to make your files writables, make your changes to it, then you add it to the pending changes, and finally check it in.

Here is some code where a folder structure is created and then checked in (Very similar to what you will need).

    private static void CreateNodes(ItemCollection nodes)
{
    using (var tfs = TeamFoundationServerFactory.GetServer("http://tfsserver:8080"))
    {
        var versionControlServer = tfs.GetService(typeof (VersionControlServer)) as VersionControlServer;
        versionControlServer.NonFatalError += OnNonFatalError;

        // Create a new workspace for the currently authenticated user.             
        var workspace = versionControlServer.CreateWorkspace("Temporary Workspace", versionControlServer.AuthenticatedUser);

        try
        {
            // Check if a mapping already exists.
            var workingFolder = new WorkingFolder("$/testagile", @"c:\tempFolder");

            // Create the mapping (if it exists already, it just overides it, that is fine).
            workspace.CreateMapping(workingFolder);

            // Go through the folder structure defined and create it locally, then check in the changes.
            CreateFolderStructure(workspace, nodes, workingFolder.LocalItem);

            // Check in the changes made.
            workspace.CheckIn(workspace.GetPendingChanges(), "This is my comment");
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        finally
        {
            // Cleanup the workspace.
            workspace.Delete();

            // Remove the temp folder used.
            Directory.Delete("tempFolder", true);
        }
    }
}

private static void CreateFolderStructure(Workspace workspace, ItemCollection nodes, string initialPath)
{
    foreach (RadTreeViewItem node in nodes)
    {
        var newFolderPath = initialPath + @"\" + node.Header;
        Directory.CreateDirectory(newFolderPath);
        workspace.PendAdd(newFolderPath);
        if (node.HasItems)
        {
            CreateFolderStructure(workspace, node.Items, newFolderPath);
        }
    }
}

Using the other solution gave me permission problems.

Here's an alternative way to checkout your files using tf.exe:

//Checkout file
Process proc = new Process();
proc.StartInfo = 
    new ProcessStartInfo(
        @"C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\tf.exe", 
        string.Format("checkout \"{0}\"", fileLocation)
    );
proc.StartInfo.UseShellExecute = false;
proc.Start();
proc.WaitForExit();