string tempKYCFolderPath = "~/Attachments/KYC/KYCTemp/";
string zipfolder = tempKYCFolderPath + "Userdata/";

DirectoryInfo tempPoposalFolder = new DirectoryInfo(HostingEnvironment.MapPath(zipfolder));

if (!tempPoposalFolder.Exists)
{
    tempPoposalFolder.Create();
}

string tempUserFolderPath = Path.Combine(tempPoposalFolder.FullName, dr["User Id"] + "_" + dr["Name"].ToString().Trim());
string fileNameAppend = "kyc_" + dr["User Id"].ToString();

DirectoryInfo tempUserFolder = new DirectoryInfo(tempUserFolderPath);

if (!tempUserFolder.Exists)
{
    tempUserFolder.Create();
}

if (dr["PassportFile"] != DBNull.Value)
{
    FileInfo file = new FileInfo(HostingEnvironment.MapPath(Path.Combine(tempKYCFolderPath, dr["PassportFile"].ToString())));

    if (file != null && file.Exists)
    {
        file.CopyTo(HostingEnvironment.MapPath(Path.Combine(tempUserFolderPath , fileNameAppend + "PassportFile" + file.Extension)), true);
    }
}

字符串
我试图创建一个文件夹，并在另一个文件夹内，然后从一个位置复制文件，并希望将其粘贴到第二个文件夹内，但我得到一个错误
System.ArgumentException
HResult=0x80070057
Message=此处不允许使用相对虚拟路径“C：/eureeca/solution_Ap3/KYC/KYCTemp/Userdata/7_aseel amas amassi/kyc_7PassportFile.jpg”。
来源=App_Web_jtqcblog
StackTrace：
在Crowd_funding_pages_Admin_UserNiNList.ExporttoCsv（String userid）在c：\eureeca\solution_Ap3\Crowd-funding-pages\Admin\UserNiNList.aspx.cs：行139
此异常最初在此调用堆栈中引发：
[外部代码]
UserNiNList.aspx.cs中的Crowd_funding_pages_Admin_UserNiNList.ExporttoCsv（字符串）”