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");

Sadly none of the answer tells the exact root cause, https://learn.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." — Lex Li, Feb 02 '20 at 22:19
thanks @LexLi this means that the better solution is to set `UseShellExecute = true` — Bizhan, Feb 03 '20 at 09:27

score 8 · Accepted Answer · edited Jul 18 '19 at 08:23

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");

Thank you very much! It's help me a lot. We can add this url = url.Replace("&", "^&"); before Process.Start(new ProcessStartInfo("cmd", $"/c start {url}") { CreateNoWindow = true }); Because cmd.exe will recognize ^& into &. — Milo Chen, Jul 07 '20 at 22:13
This is a great answer. I've been looking for a cross platform way to launch a local HTML file in a browser, and this is it! — RichMercer, Jan 13 '22 at 09:50

score 6 · Answer 2 · answered Nov 17 '20 at 00:04

The exact root cause is indicated here: https://learn.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.

LOAS · Answer 3 · 2020-11-18T13:23:45.233

1

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 :)

edited Nov 18 '20 at 13:23

answered Nov 18 '20 at 12:14

LOAS

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score 0 · Answer 4 · edited Jun 20 '20 at 09:12

Windows Run window (Win+R) know how to resolve "microsoft-edge:" to the Path Of Executable. When you call it through Run window, it first resolves to the path. Then the actual executable from that path is executed.

With Process.Start, there is no this resolution of path. It only look for some paths like application path or PATH variables. Obviously, it does not find the executable to run and hence the error.

If you have a path variable declared in your system using quotes, you must fully qualify that path when starting any process found in that location. Otherwise, the system will not find the path. For example, if c:\mypath is not in your path, and you add it using quotation marks: path = %path%;"c:\mypath", you must fully qualify any process in c:\mypath when starting it.

Source

Note that command line parameters are not allowed by this overload:

This overload does not allow command-line arguments for the process. If you need to specify one or more command-line arguments for the process, use the Process.Start(ProcessStartInfo) or Process.Start(String, String) overloads.

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

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