Microsoft.VisualStudio.Project.ProjectNode.UpgradeProject C# (CSharp) Method

        public int UpgradeProject(uint grfUpgradeFlags)
        {
            int hr = VSConstants.S_OK;

            if (!PerformTargetFrameworkCheck())
            {
                // Just return OLE_E_PROMPTSAVECANCELLED here which will cause the shell
                // to leave the project in an unloaded state.
                hr = VSConstants.OLE_E_PROMPTSAVECANCELLED;
            }

            return hr;
        }