I have my main method static async Task Main(string[] args) and another async method public static async Task c8y_pushEvent(string Event_MSG) inside my class Program. I'm trying to call the public static async Task c8y_pushEvent(string Event_MSG) from inside static async Task Main(string[] args).

class Program
{
    int int_lastPushedId = 235;
    int get_maxID_old = 250;
    string c8y_Event_MSG = String.Empty;

    static async Task Main(string[] args)
    {
        //Here's where I am getting the problem.
        for(int event_dbID_lp = int_lastPushedId   1 ; event_dbID_lp <= get_maxID_old ; event_dbID_lp  )
                {
                SqlCommand command4 = new SqlCommand(queryString4, connection);
                command4.Parameters.Add("@ID", (int)event_dbID_lp);
                SqlDataReader reader4 = command4.ExecuteReader();

                    while (reader4.Read())
                    {
                        c8y_Event_MSG = Convert.ToString(reader4[0]);
                        await c8y_pushEvent(c8y_Event_MSG);
                    }
                    reader4.Close();
                }
     }

     public static async Task c8y_pushEvent(string Event_MSG)
    {
        var serviceCollection = new ServiceCollection();
        ConfigureServices(serviceCollection);
        var services = serviceCollection.BuildServiceProvider();
        var httpClientFactory = services.GetRequiredService<IHttpClientFactory>();

        List<KeyValue> keyvalue = JsonConvert.DeserializeObject<List<KeyValue>>(Event_MSG);
        string controllerName = keyvalue[0].ToString();
        JArray EventMSG = JArray.Parse(Event_MSG);
        var item = EventMSG[0];

        var httpClientgetControllerId = httpClientFactory.CreateClient("getControllerId");
        var httpClientcreateGolfControllerEvent = httpClientFactory.CreateClient("createGolfControllerEvent");

        var request1 = await httpClientgetControllerId.GetAsync($"abc/xyz/{controllerName}");
        if (request1.IsSuccessStatusCode)
        {
            HttpResponseMessage request2 = await httpClientcreateGolfControllerEvent.PostAsync("event/events", stringContent);
            //stringContent is fetched from some other lines which I've not 
            //included here
        }
     }

     private static void ConfigureServices(ServiceCollection services)
    {

        services.AddHttpClient("getControllerId", options =>
        {
            options.BaseAddress = new Uri("https://myurl.com/");

            options.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic","auth_value");
        });

        services.AddHttpClient("createGolfControllerEvent", options =>
        {
            options.BaseAddress = new Uri("https://myurl.com/");
            options.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic","auth_value");
            options.DefaultRequestHeaders.Add("Accept", "application/vnd.com.nsn.xyz.event json");
        });
     }

     public class KeyValue
    {
        [JsonProperty("ControllerName")]
        public string ControllerName { get; set; }
        public override string ToString()
            {
                return String.Format(ControllerName.ToString());
            }
    }
}

I'm getting the error

An object reference is required for the non-static field, method, or property 'Program.c8y_Event_MSG' [deserializeJSON]

on line

await c8y_pushEvent(c8y_Event_MSG);

How can I fix this issue?

Additional question:

The difference between int_lastPushedId and get_maxID_old can be as big as 1000 hence there can be 1000 iterations. Is my implementation of IHttpClientFactory suitable for this, making sure there's no exhaustion of socket/ports?

CodePudding user response：

Main error

It looks like c8y_Event_MSG should be local:

while (reader4.Read())
{
     var c8y_Event_MSG = Convert.ToString(reader4[0]);
     await c8y_pushEvent(c8y_Event_MSG);
}

HttpClient qestion

All of the Dependency Injection code seem unnecessary. I cannot think of a situation where var serviceCollection = new ServiceCollection(); in a for loop would be a good idea.

Here's a simpler version that should do the job:

class Program
{
    static HttpClient httpClient;

    static async Task Main(string[] args)
    {
       httpClient = new HttpClient();

       //Setup auth and base address 

       for(...)
       {
          ...
          c8y_pushEvent(...)
       }
    } 

    public static async Task c8y_pushEvent(string Event_MSG, HttpClient)
    {
        List<KeyValue> keyvalue = JsonConvert.DeserializeObject<List<KeyValue>>(Event_MSG);
        string controllerName = keyvalue[0].ToString();
        JArray EventMSG = JArray.Parse(Event_MSG);
        var item = EventMSG[0];

        var request1 = await httpClient.GetAsync($"abc/xyz/{controllerName}");
     }