RestSharp Get请求无法发送请求体问题求助（.NET Framework 4.8）

问题分析 #

你遇到的情况是API强制要求用GET方法但需要传递JSON请求体，RestSharp出于HTTP规范的默认限制阻止了GET请求携带RequestBody，同时POST方法又被API拒绝，得绕开RestSharp的限制来实现调用。

解决方案：使用HttpWebRequest实现 #

直接用.NET Framework自带的HttpWebRequest可以强制发送带请求体的GET请求，不受RestSharp的限制，代码如下：

Dim url As String = "https://smartlane.com.pk/api/production/consignment/track"
Dim jsonBody As String = "{" & vbLf & "    ""store_order_id"":[" & vbLf & "        ""1001"",""1002""" & vbLf & "    ]" & vbLf & "}"

' 创建请求对象
Dim request As HttpWebRequest = DirectCast(WebRequest.Create(url), HttpWebRequest)
request.Method = "GET"
request.ContentType = "application/json"
request.Headers.Add("Authorization", "kA0HzgWQRaYRepL8ol8jmkHVJJIZRDQfx1zEqB")

' 写入请求体
Using streamWriter As New StreamWriter(request.GetRequestStream())
    streamWriter.Write(jsonBody)
End Using

' 获取响应
Try
    Using response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)
        Using streamReader As New StreamReader(response.GetResponseStream())
            Dim responseContent As String = streamReader.ReadToEnd()
            Console.WriteLine(responseContent)
        End Using
    End Using
Catch ex As WebException
    ' 处理异常，读取错误响应内容
    Using errorResponse As HttpWebResponse = DirectCast(ex.Response, HttpWebResponse)
        Using streamReader As New StreamReader(errorResponse.GetResponseStream())
            Dim errorContent As String = streamReader.ReadToEnd()
            Console.WriteLine("请求错误：" & errorContent)
        End Using
    End Using
End Try

补充说明 #

1. HTTP规范中GET方法不推荐携带请求体，但部分API厂商会出于特殊需求这么设计，原生的HttpWebRequest不会做额外限制，能满足这类场景。
2. 如果坚持要用RestSharp，需确保使用RestSharp 107及以上版本，并通过配置启用GET带请求体的支持：

Dim client = New RestClient("https://smartlane.com.pk/api/production/consignment/track")
client.Options.AllowGetMethodBody = True ' 开启GET带body的支持

Dim request = New RestRequest()
request.Method = Method.Get
request.AddHeader("Authorization", "kA0HzgWQRaYRepL8ol8jmkHVJJIZRDQfx1zEqB")
request.AddHeader("Content-Type", "application/json")
Dim body = "{" & vbLf & "    ""store_order_id"":[" & vbLf & "        ""1001"",""1002""" & vbLf & "    ]" & vbLf & "}"
request.AddStringBody(body, ContentType.Json)

Dim response = client.Execute(request)
Console.WriteLine(response.Content)

注意：旧版本RestSharp没有AllowGetMethodBody配置项，此时原生HttpWebRequest是更稳妥的选择。

内容的提问来源于stack exchange，提问作者Samee Ullah