“The process cannot access the file because it is being used by another process” c#

Question

I want to run an exe file using process in c#, the output when i will run the exe file will be the string of the char pressed on the keyboerd and it will be printed to the process using RedirectStandardOutput = true . i will recive a byte[] that contains the file and will convert it to file, then make a new process that will activate the file and my intention is to read the out from the file(the string/char pressed by the keyboerd) and see it in the TB which is a TextBlock(I'm working on WPF). but when i run it it print the excaption mentioned above. here is my code:

private void p1()
{
   byte[] b1 = the byte[] containing the file;

   FileStream file = File.Create("p.exe");
   file.Write(b1, 0, b1.Length);
   try
       {
          var process = new Process
          {
           StartInfo = new ProcessStartInfo
             {
               FileName = file.Name,
               UseShellExecute = false,
               RedirectStandardOutput = true,
               CreateNoWindow = true
              }
          };

          Thread t = new Thread(() => { res = ReadFromP(process); });
          t.Start();
          t.Join();
          TB.Text=res;


       }

   catch
    {
       TB.text="didnt worked";
    }
}

private string ReadFromP(Process p)
{
 try
  {
   string line;
   p.Start();
   // while (!p.StandardOutput.EndOfStream)
   //{
   line = p.StandardOutput.ReadLine();
   //} 
   return line;
   //p.WaitForExit();

   }


  catch (Exception e)
  {
     return(e.Message);
  }
}

Answer 1

FileStream file = File.Create("p.exe");

Here you are opening a stream. This one is never closed. So when you are trying to access it at a later point it will be already in use and cannot be opened. You need to close it by either wrapping a using statement around the usage or add file.Close() when you are done working with the file.

using (var file = File.Create("p.exe"))
        {

        }

or

file.Close();