如何将restsharp代码转换为包含文件的httpclient

using System.Net.Http;
using System.Net.Http.Headers;
using System.IO;

HttpClient client = new HttpClient();

client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("multipart/form-data"));

MultipartFormDataContent formData = new MultipartFormDataContent();
FileStream fileStream = File.OpenRead("文件路径");
formData.Add(new StreamContent(fileStream), "file", "文件名");

string url = "目标URL";
HttpResponseMessage response = await client.PostAsync(url, formData);

if (response.IsSuccessStatusCode)
{
    string result = await response.Content.ReadAsStringAsync();
    // 处理成功响应结果
}
else
{
    // 处理错误响应
}