Elevating privileges doesn't work with UseShellExecute=false

I want to start a child process (indeed the same, console app) with elevated privileges but with hidden window.

I do next:

var info = new ProcessStartInfo(Assembly.GetEntryAssembly().Location)
{
    UseShellExecute = true, // !
    Verb = "runas", 
};

var process = new Process
{
    StartInfo = info
};

process.Start();

and this works:

var identity = new WindowsPrincipal(WindowsIdentity.GetCurrent());
identity.IsInRole(WindowsBuiltInRole.Administrator); // returns true

But UseShellExecute = true creates a new window and I also I can't redirect output.

So when I do next:

var info = new ProcessStartInfo(Assembly.GetEntryAssembly().Location)
{
    RedirectStandardError = true,
    RedirectStandardOutput = true,
    UseShellExecute = false, // !
    Verb = "runas"
};

var process = new Process
{
    EnableRaisingEvents = true,
    StartInfo = info
};

DataReceivedEventHandler actionWrite = (sender, e) =>
{
    Console.WriteLine(e.Data);
};

process.ErrorDataReceived += actionWrite;
process.OutputDataReceived += actionWrite;

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

This doesn't e开发者_StackOverflow中文版levate privileges and code above returns false. Why??

ProcessStartInfo.Verb will only have an effect if the process is started by ShellExecuteEx(). Which requires UseShellExecute = true. Redirecting I/O and hiding the window can only work if the process is started by CreateProcess(). Which requires UseShellExecute = false.

Well, that's why it doesn't work. Not sure if forbidding to start a hidden process that bypasses UAC was intentional. Probably. Very probably.

Check this Q+A for the manifest you need to display the UAC elevation prompt.

In my case, it was ok to get the outputs once the elevated child process is done. Here's the solution I came up. It uses a temporary file :

var output = Path.GetTempFileName();
var process = Process.Start(new ProcessStartInfo
{
    FileName = "cmd",
    Arguments = "/c echo I'm an admin > " + output, // redirect to temp file
    Verb = "runas", // UAC prompt
    UseShellExecute = true,
});
process.WaitForExit();
string res = File.ReadAllText(output);
// do something with the output
File.Delete(output);

Check this answer.

This seems to provide a workaround. But I recommend to try other methods like Named Pipes when you have access to source code of the child process.