File.Delete无法删除文件，因为它正在被另一个进程使用。 不确定如何解决此问题

Question

I have a project where I have a web form that generates a .csv file on the fly and then is encrypted using GnuPG. The encryption process works and the encrypted file is generated in the same directory. Next, after the file is encrypted, I need for the regular .csv file to be deleted.

I have used file.delete to do this but I am getting the error "The process cannot access the file 'FILEPATH/FILENAME.EXT' because it is being used by another process. I am unsure if I placed the code in the wrong area.

Can anyone suggest to me what I should do? Here is the relevant code.

public void encryptPGP(string fileName)
{
    try
    {
        string sCommandLine = String.Format(@"-r ""CERT NAME"" -e ""{0}""", fileName);
       //lblError.Text = "<pre>" + sCommandLine + "</pre>";

        string userPwd = "COOLPWD";
        System.Security.SecureString pwd = new System.Security.SecureString();
        foreach (char c in userPwd.ToCharArray())
        {
            pwd.AppendChar(c);
        }

        System.Diagnostics.ProcessStartInfo info = new System.Diagnostics.ProcessStartInfo();
        info.Arguments = sCommandLine;
        info.Domain = "DOMAINNAME";
        info.FileName = "C:\\Utilities\\GnuPG\\App\\gpg.exe";
        info.Password = pwd;
        info.UserName = "USERNAME";
        info.UseShellExecute = false;
       info.RedirectStandardOutput = true;
       info.CreateNoWindow = true;
        info.WorkingDirectory = "C:\\Utilities\\GnuPG\\App\\";

        //writeToLog(info.FileName, "App");
        //writeToLog(sCommandLine, "Args");

       System.Diagnostics.Process proc = new System.Diagnostics.Process();
       proc.StartInfo = info;
        proc.Start();
       lblError.Text = proc.StandardOutput.ReadToEnd();

    System.IO.File.Delete(fileName);

    }
    catch (Exception ex)
    {
       lblError.Text = ex.Message;
        //writeToLog(ex.Message, "");
    }
}

// method for writing error log
private void writeToLog(string strMessage, string strMethod)
{
    using (System.IO.StreamWriter file = new System.IO.StreamWriter(@"C:\\Log.txt", true))
    {
        file.WriteLine(string.Format("{0} - {1} - {2}", DateTime.Now, strMethod, strMessage));
    }
}
// end method for writing error log

Also, here is the process to create the file:

        string fileName = @"c:\DIR\DIR\" + pt.SelectedItem.Value + pcf + "--" + usname + "--" + sname.Text + "--" + cdt + ".csv";
    string lines = DropDownList3.SelectedItem.Value + "," + DropDownList8.SelectedItem.Value + "," + DropDownList1.SelectedItem.Value + "," + TextBox25.Text + "," + ssn.Text + "," + TextBox13.Text + "," + Lastname.Text + "," + firstname.Text + "," + " " + "," + TextBox1.Text + "," + TextBox3.Text + "," + TextBox4.Text + "," + TextBox5.Text + "," + TextBox6.Text + "," + TextBox9.Text + "," + TextBox10.Text + "," + TextBox11.Text + "," + TextBox2.Text + "," + " " + "," + TextBox22.Text + "," + TextBox26.Text + "," + TextBox29.Text + "," + TextBox19.Text + "," + TextBox27.Text + "," + TextBox30.Text + "," + TextBox24.Text + "," + TextBox28.Text + "," + TextBox8.Text + "," + DropDownList7.SelectedItem.Value + "," + TextBox38.Text + " " + TextBox34.Text + "," + TextBox33.Text + "," + TextBox41.Text + "," + TextBox35.Text + "," + TextBox36.Text + "," + TextBox37.Text + "," + TextBox54.Text + "," +" "+"," + TextBox12.Text;
    System.IO.File.WriteAllText(fileName, lines);

    encryptPGP(fileName);

Answer 1

I would say it is likely that GnuPG is still using the file when you try to delete it.

You need to wait for the process to end before doing the deletion, ie add:

proc.WaitForExit(); 

directly before

System.IO.File.Delete(fileName); 

Answer 2

Have you closed the write stream when you create the file. That will be it. You need to close the stream then delete.

Whatever code you have that creates this file must have a stream of some description. Check if there is a Close method on it. Can you post the code that creates the file in the first place?