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

        protected virtual int CanOverwriteExistingItem(string originalFileName, string computedNewFileName)
        {
            if (String.IsNullOrEmpty(originalFileName) || String.IsNullOrEmpty(computedNewFileName))
            {
                return VSConstants.E_INVALIDARG;
            }

            string message = String.Empty;
            string title = String.Empty;
            OLEMSGICON icon = OLEMSGICON.OLEMSGICON_CRITICAL;
            OLEMSGBUTTON buttons = OLEMSGBUTTON.OLEMSGBUTTON_OK;
            OLEMSGDEFBUTTON defaultButton = OLEMSGDEFBUTTON.OLEMSGDEFBUTTON_FIRST;

            // If the document is open then return error message.
            IVsUIHierarchy hier;
            IVsWindowFrame windowFrame;
            uint itemid = VSConstants.VSITEMID_NIL;

            bool isOpen = VsShellUtilities.IsDocumentOpen(this.Site, computedNewFileName, Guid.Empty, out hier, out itemid, out windowFrame);

            if (isOpen)
            {
                message = String.Format(CultureInfo.CurrentCulture, SR.GetString(SR.CannotAddFileThatIsOpenInEditor, CultureInfo.CurrentUICulture), Path.GetFileName(computedNewFileName));
                VsShellUtilities.ShowMessageBox(this.Site, title, message, icon, buttons, defaultButton);
                return VSConstants.E_ABORT;
            }

            // File already exists in project... message box
            message = SR.GetString(SR.FileAlreadyInProject, CultureInfo.CurrentUICulture);
            icon = OLEMSGICON.OLEMSGICON_QUERY;
            buttons = OLEMSGBUTTON.OLEMSGBUTTON_YESNO;
            int msgboxResult = VsShellUtilities.ShowMessageBox(this.Site, title, message, icon, buttons, defaultButton);
            if (msgboxResult != NativeMethods.IDYES)
            {
                return (int)OleConstants.OLECMDERR_E_CANCELED;
            }

            return VSConstants.S_OK;
        }