使用httpwebrequest调用ibm watson discovery adddocument api

using System;
using System.IO;
using System.Net;
using System.Text;

string apiKey = "YOUR_API_KEY";
string collectionId = "YOUR_COLLECTION_ID";
string url = $"https://api.us-south.discovery.watson.cloud.ibm.com/instances/YOUR_INSTANCE_ID/v1/environments/YOUR_ENVIRONMENT_ID/collections/{collectionId}/documents?version=2019-04-30";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "POST";
request.Headers.Add("Authorization", "Bearer " + apiKey);
request.ContentType = "application/json";

string documentJson = @"
{
    ""file"": ""<FILE_CONTENT>"",
    ""filename"": ""<FILE_NAME>"",
    ""file_content_type"": ""<FILE_CONTENT_TYPE>""
}";

byte[] documentData = Encoding.UTF8.GetBytes(documentJson);

using (Stream requestStream = request.GetRequestStream())
{
    requestStream.Write(documentData, 0, documentData.Length);
}

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
    using (StreamReader reader = new StreamReader(response.GetResponseStream()))
    {
        string responseJson = reader.ReadToEnd();
        // 处理响应数据
    }
}