C# GeckoFX v45 cannot set GeckoPreferences to set proxy

Question

I am using GeckoFx v45 and I am trying to set different proxy. I tried the following which should normally work.

private void Form1_Load(object sender, EventArgs e)
        {
            try
            {
                Xpcom.Initialize("Firefox"); //just in case its not already loaded
                GeckoPreferences.User["general.useragent.override"] = UA;
                GeckoPreferences.User["network.proxy.type"] = 1;
                //replaced by normal valid proxy and port
                GeckoPreferences.User["network.proxy.http"] = "1.1.1.1";
                GeckoPreferences.User["network.proxy.http_port"] = "1234";
                GeckoPreferences.User["network.proxy.ssl"] = "1.1.1.1";
                GeckoPreferences.User["network.proxy.ssl_port"] = "1234";

                geckoWebBrowser1.Navigate(textBox1.Text);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.InnerException.Message);
            }
        }

The GeckoBrowser will never load and it will remain black. In the output i see a 'System.InvalidCastException' in Geckofx-Core.dll. In the metadata I see this from the DLL,

public static GeckoPreferences Default { get; }
public static GeckoPreferences User { get; }

and I am wondering how can we set that Property while it is get-only. I think this is the issue that is not letting my browser load. When I remove the GeckoPreferences and simply Navigate the browser, it works, but without Proxy obviously.

If this is the issue then how can I properly set the proxy on a Gecko Webbrowser?

wp78de · Accepted Answer · 2019-09-12T18:56:09.743

This seems to be a simple issue. When I added your code to my sample I got a runtime error:

Additional information: A String value may not be assigned to 'network.proxy.http_port' because it is already defined as Int32.

So, 'network.proxy.http_port/ssl_port' needs to be an integer:

GeckoPreferences.User["network.proxy.http_port"] = 1234;

GeckoPreferences.User["network.proxy.http_port"] = 6789;

You may also want to look at:

C# GeckoFX v45 cannot set GeckoPreferences to set proxy

1 Answers1