Process.Start("microsoft-edge:") throws Win32Exception in dot net core

Question

When I execute the following line of code:

Process.Start("microsoft-edge:");

Or

Process.Start("microsoft-edge:http://localhost");

It gives me this error:

System.ComponentModel.Win32Exception: 'The system cannot find the file specified.'

When I run microsoft-edge: using Win+R it works.

When I run the same code in .net framework it works.

I'm using .netcore 3.0.0-preview6-27804-01

Any idea why this is happening?

---

Edit:

These are not working either:

Process.Start(@"c:\Windows\System32\LaunchWinApp.exe:http://localhost");
Process.Start(@"http://localhost");

All other executables on my system work.

Also this is working too but I can't open a specific webpage with it:

Process.Start("explorer", @"shell:Appsfolder\Microsoft.MicrosoftEdge_8wekyb3d8bbwe!MicrosoftEdge");

Answer 1

You cannot simply open a url with the expected call Process.Start("url");

You have to create a ProcessStartInfo and pass your browser and url as arguments:

Process.Start(new ProcessStartInfo("cmd", $"/c start microsoft-edge:http://localhost") { CreateNoWindow = true });

(edit) The use of ProcessStartInfo is required because we need to set its CreateNoWindow = true to prevent cmd window from showing up.

But as this code not only can be run on a Windows machine, i'd consider using something more cross-platform specific like this (https://brockallen.com/2016/09/24/process-start-for-urls-on-net-core/):

public void OpenBrowser(string url)
{
    try
    {
        Process.Start(url);
    }
    catch
    {
        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
        {
            Process.Start(new ProcessStartInfo("cmd", $"/c start {url}") { CreateNoWindow = true });
        }
        else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
        {
            Process.Start("xdg-open", url);
        }
        else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
        {
            Process.Start("open", url);
        }
        else
        {
            throw;
        }
    }
}

And call it with OpenBrowser("http://localhost");

Answer 2

The exact root cause is indicated here: https://docs.microsoft.com/en-us/dotnet/api/system.diagnostics.processstartinfo.useshellexecute?view=netframework-4.8

"The default is true on .NET Framework apps and false on .NET Core apps."

This means the direct solution is to set UseShellExecute. The following is basically the same as the original except making an explicit Process object to modify a setting.

       Process pWeb = new Process();
       pWeb.StartInfo.UseShellExecute = true;
       pWeb.StartInfo.FileName = "microsoft-edge:http://localhost";
       pWeb.Start();

Credit to @Lex Li and @Bizhan for their comments leading to this solution.

Answer 3

This variation seems to do the job as well:

Process.Start(new ProcessStartInfo("msedge") { 
  UseShellExecute = true, 
  Arguments = "http://localhost" });

It avoids the strangeness of the microsoft-edge:<url> syntax thus allowing for more chrome arguments to be passed in the usual way.

If anyone knows of a reason to avoid this, feel free to speak up :)