Open a default browser window using c# and Process.Start

Question

I am trying to open a web page using the default browser when someone hits an API endpoint.

I have this working on my local test machine:

    [HttpGet("Http/{classId}")]
    public void OpenWebLink(Guid classId)
    {
        string target = "http://astrolab.meeting.trl.edu/class/details.aspx?classId=" + classId;
        System.Diagnostics.Process.Start("C:\\Program Files\\Mozilla Firefox\\firefox.exe", target);
    }

But when I publish to a server that has IIS, it can't find firefox.exe

The problem is, I had to put the full path to firefox just to get it to work on my machine. If I didn't include the path like that I'd get this error:

System.Diagnostics.Process.Start Win32Exception: 'The system cannot find the file specified.'

I also tried this:

    [HttpGet("Http")]
    public void OpenWebLink(Guid classId)
    {
        try
        {

            var ps = new ProcessStartInfo("http://astrolab.meeting.trl.edu/class/details.aspx?classId=" + classId;)
            {
                Verb = "open"
            };
        Process.Start(ps);
        }
        catch (Win32Exception w32Ex) 
        {
            throw w32Ex;
        }
    }

But it still fails when I hit the endpoint on the IIS server with this:

System.ComponentModel.Win32Exception (2): The system cannot find the file specified.

Is there a way to set it up so that it will find the default browser on any machine?

Thanks!

Instead of specifying the browser, just specify the URL (see https://stackoverflow.com/questions/4580263/how-to-open-in-default-browser-in-c-sharp) — Gus, Nov 09 '20 at 18:01
@Gus Hi! I did try that, but unfortunately it just returns a `Win32Exception` stating that it can't find the file specified. — SkyeBoniwell, Nov 09 '20 at 18:02

score 2 · Accepted Answer · answered Nov 09 '20 at 18:12

2

Either use ShellExecute to launch your url (the more correct way), or pipe it through explorer (the lazier, less portable way).

Process.Start(new()
{
    UseShellExecute = true,
    FileName = "http://google.ca",
});

Process.Start("explorer.exe", "http://google.ca");

answered Nov 09 '20 at 18:12

Blindy

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thank you, so I would use `UseShellExecute` if I wanted it to work on most machines using that machines default browser? When using `UseShellExecute` do I exclude the name of the browser in `Process.Start` ? thanks – SkyeBoniwell Nov 09 '20 at 18:20
Hi when I tried this, Visual Studio is indicating an error here: `Process.Start(new()`, ... the keyword `new` is underlined and says `The feature 'target-typed object creation' is currently in Preview and *unsupported*. To use Preview features, use the 'preview' language version.` – SkyeBoniwell Nov 09 '20 at 18:23
That is correct, yes. Are you asking how to use C# 9? Or how to instantiate a class in C# 8 or below? – Blindy Nov 09 '20 at 18:51
I am using .net 3.1 so I hope it's whatever c# version comes with that. I can try to upgrade if it helps thanks – SkyeBoniwell Nov 09 '20 at 19:06
You can use `Process.Start(new ProcessStartInfo { ... };` in C#8. I recommend reading about classes if that was indeed your question. – Blindy Nov 09 '20 at 19:10
So I tried it, you can see the new code above. And it still fails when I publish it to my IIS server. It works locally though. Maybe that code is trying to open the browser on the IIS server and not the client machine? – SkyeBoniwell Nov 09 '20 at 19:24
1

Yes, of course, it opens the window on the machine on which it runs. – Blindy Nov 09 '20 at 19:26
thanks, I think that's where my logic failed. I was thinking that it would open the browser on the client machine and not the server :/ – SkyeBoniwell Nov 09 '20 at 20:09
1

Can you imagine the security risks if any web page could start executing random programs on your computer? That will never happen! – Blindy Nov 09 '20 at 20:22

Open a default browser window using c# and Process.Start

1 Answers1