Misused header 'content-type' Async

[Sven286]

Hi,

I just started to use this nuget package for connecting to the api of my zabbix 6.0.23 installation.
I created my new project as .Net 8 application and want to use asynchrone methods.
Receiving all host groups gives me the following exception.

var groups = await _zabbixCore.HostGroups.GetAsync()

System.InvalidOperationException: Misused header name, 'content-type'. Make sure request headers are used with HttpRequestMessage, response headers with HttpResponseMessage, and content headers with HttpContent objects.
   at System.Net.Http.Headers.HttpHeaders.GetHeaderDescriptor(String name)
   at System.Net.Http.Headers.HttpHeaders.Add(String name, String value)
   at Zabbix.Core.ZabbixCore.SendRequestAsync[T](Object params, String method, String token)
   at Zabbix.Core.ZabbixCore.SendRequestAsync[T](Object params, String method)
   at Zabbix.Services.CrudServices.GetService`2.GetAsync(TEntityFilter filter)
   at Zabbix.Services.CrudServices.CrudService`3.GetAsync(TEntityFilter filter)

When I call the method synchroniously everything works fine.
var groups = _zabbixCore.HostGroups.Get()

I Suspect the following line of code to be the issue, but I don't know why this piece is added:

Zabbix-6.0-Api/Zabbix/Core/ZabbixCore.cs

Line 134 in 39d73b0

_httpClient.DefaultRequestHeaders.Add("content-type", "application/json-rpc");

[stefan-epic]

I will look into this when I get the time thanks for making the issue :)

[Scriptman]

Just remove the line 134 in ZabbixCore.cs:
this._httpClient.DefaultRequestHeaders.Add("content-type", "application/json-rpc");

It's in the SendRequestAsync(object? @params, string method, string? token) method.

You don't use this in the non-Async request.