Question

I’m making MSI installer in WiX. During installation I want to run an executable from a custom action and get its standard output (not the return code) for later use during installation (with Property element, supposedly).

How can I achieve it in WiX (3.5)?

Answer 1

I used this code for a similar task (its a C# DTF custom action):

// your process data
ProcessStartInfo processInfo = new ProcessStartInfo() {
   CreateNoWindow = true,
   LoadUserProfile = true,
   UseShellExecute = false,
   RedirectStandardOutput = true,
   StandardOutputEncoding = Encoding.UTF8,
   ...
};

Process process = new Process();
process.StartInfo = processInfo;
process.OutputDataReceived += (object sender, DataReceivedEventArgs e) =>
  {
     if (!string.IsNullOrEmpty(e.Data) && session != null)
     {
         // HERE GOES THE TRICK!
         Record record = new Record(1);
         record.SetString(1, e.Data);
         session.Message(InstallMessage.ActionData, record);
      }
  };

process.Start();
process.BeginOutputReadLine();
process.WaitForExit();

if (process.ExitCode != 0) {
   throw new Exception("Execution failed (" + processInfo.FileName + " " + processInfo.Arguments + "). Code: " + process.ExitCode);
}

process.Close();