When I run this code, I get an exception:

System.InvalidCastException: Unable to cast object of type 'System.Dynamic.ExpandoObject' to type 'System.Collections.Generic.IEnumerable`1[System.Collections.Generic.KeyValuePair`2[System.String,System.String]]'.

I am trying to pass this to a POST that takes parameters. Not sure how to do this?

using System.Dynamic; // ExpandObject
using System.Net.Http;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;

...

       var s = @"
        {
          ""time-in-force"": ""Day"",
          ""order-type"": ""Limit"",
          ""price"": ""2.0"",
          ""price-effect"": ""Credit"",
          ""legs"": [
             {
             ""instrument-type"": ""Equity Option"",
              ""symbol"": ""SPY   191018C00298000"",
              ""quantity"": 1,
              ""action"": ""Buy to Open""
             },
             {
             ""instrument-type"": ""Equity Option"",
              ""symbol"": ""SPY   191018C00295000"",
              ""quantity"": 1,
              ""action"": ""Sell to Open""
            }
          ]
        }
        ";

        try
        {
            dynamic json =
              JsonConvert.DeserializeObject<ExpandoObject>(
                s,
                new ExpandoObjectConverter()
              );

            var iProps = json as IDictionary<string, Object>;
            var furl = new FormUrlEncodedContent((IEnumerable<KeyValuePair<string, string>>)iProps);
        }
        catch(Exception ex)
        {
        }

CodePudding user response：

enter image description here

Just use "GetEnumerator" to get iProps as IEnumerable<KeyValuePair<string, object>> then you can iterate it and store it in List<KeyValuePair<string, string>>