System.IndexOutOfRangeException: 'Index was outside the bounds of the array.'

Question

First of all - I know this question has been asked. I hardly know C# still learning, a lot of this code is from a tutorial, so I was hoping if I could have a more of direct answer to my actual code. Im making a twitch bot.

 private void ViewListUpdate()
    {
        ViewerBox.Items.Clear();
        Chatters AllChatters = ChatClient.GetChatters("name");
        chatBox.Text += "Checking the viewer list...";

        foreach (string admin in AllChatters.Admins)
        {
            ViewerBox.Items.Add(admin + Environment.NewLine);
        }

        foreach (string staff in AllChatters.Staff)
        {
            ViewerBox.Items.Add(staff + Environment.NewLine);
        }

        foreach (string globalmod in AllChatters.GlobalMods)
        {
            ViewerBox.Items.Add(globalmod + Environment.NewLine);
        }

        foreach (string moderator in AllChatters.Moderators)
        {
            ViewerBox.Items.Add(moderator + Environment.NewLine);
        }

        foreach (string viewers in AllChatters.Viewers)
        {
            ViewerBox.Items.Add(viewers + Environment.NewLine);
        }
    }

The line that is getting the error (System.IndexOutOfRangeException: 'Index was outside the bounds of the array.') is the following:

Chatters AllChatters = ChatClient.GetChatters("name");

Any help would be great, thanks.

Answer 1

Compiled DLL

I have generated a compiled DLL for you here which you can download and add to your project. You can find this here: https://dropfile.to/9hzvwVX (updated)

Now you can fetch users for a channel like so:

var dataClient = new TwitchTmiClient();
var chatters = dataClient.GetChannelViewers("someTwitchChannelName");

Chatters will now contain a list of users in the active channel, separated by ranks (admin, mod, viewer etc.)

Explanation

Because this question is relevant to my personal interests I decided to add the feature you're looking for to the library I posted in the comments: https://github.com/michidk/TwitchCSharp

Of course, downloading files is always kind of sketchy. So what I did was add a new Twitch client implementation, because chatter data is not stored on the Twitch Kraken API but on the old, https://tmi.twitch.tv API.

namespace TwitchCSharp.Clients
{
    public class TwitchTmiClient : ITwitchClient
    {
        public readonly RestClient restClient;

        public TwitchTmiClient(string url = TwitchHelper.TwitchTmiUrl)
        {
            restClient = new RestClient(url);
            restClient.AddHandler("application/json", new DynamicJsonDeserializer());
            restClient.AddHandler("text/html", new DynamicJsonDeserializer());
            restClient.AddDefaultHeader("Accept", TwitchHelper.twitchAcceptHeader);
        }
        public ViewerList GetChannelViewers(string channel)
        {
            var request = new RestRequest("group/user/{channel}/chatters");
            request.AddUrlSegment("channel", channel.ToLower());
            return restClient.Execute<ViewerList>(request).Data;
        }

        public RestRequest GetRequest(string url, Method method)
        {
            return new RestRequest(url, method);
        }

    }
}

This new Twitch client uses two models to deserialize json into:

namespace TwitchCSharp.Models
{
    public class ViewerList
    {
        [JsonProperty("_links")]
        public Dictionary<string, string> Links;
        [JsonProperty("chatter_count")]
        public int ChatterCount;
        [JsonProperty("chatters")]
        public Chatter Chatters;
    }
}

...

namespace TwitchCSharp.Models
{
    public class Chatter
    {
        [JsonProperty("moderators")] public string[] Moderators;
        [JsonProperty("staff")] public string[] Staff;
        [JsonProperty("admins")] public string[] Admins;
        [JsonProperty("global_mods")] public string[] GlobalMods;
        [JsonProperty("viewers")] public string[] Viewers;
    }
}

A repository where you can see all the changes can be found here: https://github.com/nbokmans/TwitchCSharp/commit/ec38eecf1d0fbcb0b75c5de597a44582a61deb3d

You can git clone above repository and open it in Visual Studio to build it yourself, if you want to.