C# 安装EXCEL插件的坑

踩坑，找了半天的资料没解决,报错如下，明明与EXCEL VBA一样的代码。。。

最后自己分析VBA与C# 操作的区别，VBA是打开Excel界面操作,C# 是未开启Excel出现界面操作的

    private static void Main(string[] args)
    {
        dynamic xlsApp = Microsoft.VisualBasic.Interaction.CreateObject("Excel.Application");
        xlsApp.Visible = true;//关键的代码，否则无法完成安装
        xlsApp.Workbooks.Add();
        xlsApp.Windows(1).Visible = true;
        xlsApp.ScreenUpdating = false;
        try
        {
            var xllfi = new FileInfo(@"C:\MyExcelDna.xll");
            if (!xllfi.Exists) return;
            bool flag = false;
            for (int i = xlsApp.Addins.Count; i >= 1; i--)
            {
                var addin = xlsApp.Addins[i];
                if (addin.Name == xllfi.Name)
                {
                    if (addin.FullName != xllfi.FullName)
                    {
                        addin.Installed = false;
                        File.Delete(addin.FullName);
                        Console.WriteLine("removed old xll complete...");
                    }
                    else
                    {
                        if (addin.Installed = false)
                        {
                            addin.Installed = true;
                            flag = true;
                            Console.WriteLine("keep xll complete...");
                        }
                    }
                }
            }
            if (!flag)
            {
                xlsApp.DefaultFilePath = xllfi.DirectoryName;
                var addin = xlsApp.AddIns.Add(xllfi.FullName, false);//大部分此步骤报错的
                addin.Installed = false;
                addin.Installed = true;
                Console.WriteLine("install xll complete...");
            }
            xlsApp.Quit();
            if (xlsApp != null)
            {
                Marshal.ReleaseComObject(xlsApp);
            }
        }
        catch (Exception ex)
        {
            if (xlsApp != null)
            {
                Console.WriteLine(ex.StackTrace);
                Marshal.ReleaseComObject(xlsApp);
            }
        }
    }
}