Post 命令在 C# 应用程序中不起作用，但在 postman 中工作正常

Question

我创建了一个服务器代码，它通过 post 命令接受文件。 服务器端代码：

   app.MapPost("/upload2", async (IFormFile file) =>
   {
    List<string> validextensions = new List<string>() { ".xlsx" };
    string extension = Path.GetExtension(file.FileName);
    if (!validextensions.Contains(extension))
    {
        return $"Extention is not valid({string.Join(",", validextensions)})";
    }
    string filename = "File1" + extension;
    string path = @"D:/";
    using FileStream stream = new FileStream(Path.Combine(path, filename), FileMode.Create);
    file.CopyToAsync(stream);

    return filename;
   });

   app.MapGet("/GetToken", async (HttpContext context, IAntiforgery antiforgery) =>
   {
    // Generate the antiforgery token
    var tokens = antiforgery.GetAndStoreTokens(context);
    var requestToken = tokens.RequestToken;

    // Include the token in the response
    context.Response.ContentType = "text/plain";
    await context.Response.WriteAsync(requestToken);
   });

我相信这段代码没问题，因为它在邮递员中工作得很好。但是，我通过 C# 发送文件失败！

客户端代码：

public async Task SendExcelFileToServer(string filepath, string filename, string InnerAddress)
{
    try
    {
        // Create an instance of HttpClient
        using (var httpClient = new HttpClient())
        {
            // Set the request URI
            string requestUri = ServerAddressTextBox.Text.Trim() + InnerAddress;

            // Create multipart form data content
            using (var form = new MultipartFormDataContent())
            {
                string antiforgeryToken, cookie;
                (antiforgeryToken, cookie) = await GetAntiforgeryToken();

                // Add file part
                using (var fileContent = new ByteArrayContent(File.ReadAllBytes(filepath)))
                {
                    //form.Headers.ContentType = MediaTypeHeaderValue.Parse("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
                    //form.Add(fileContent, "file", filename);

                    // This Is obligatory inn .net8! :)
                    // Add the RequestVerificationToken header

                    form.Headers.Add("RequestVerificationToken", "CfDJ8IobTqaCf0xCi3hgie2deVpx3DCZeGmVD28L6YAsM51Szh1AF0afHexqh7O768rwdYqOqLx8ph3yM86l7bg_phwtnHFspWVdFBtKScLlooFE_10wA6HidiiMZT6TbqZsR5Q1l6C7qJ9Zcuj_1bhxt10");

                    // Add the cookie header
                    form.Headers.Add("Cookie", ".AspNetCore.Antiforgery.p8-WnM9DThg=CfDJ8IobTqaCf0xCi3hgie2deVrgEG5nQyY-SHCgXvPCDh8LFzaqG7fOX41qgeGCXUcjPKgAPvPRqEUgYhzhHLTfcnClNq5rmQIZ-CkycC_V0vzBYhSgXdCVnL_9_ftvHXhYl7S3RR575hPwsAUvKg9D8kQ");
                    //form.Headers.ContentType = MediaTypeHeaderValue.Parse("application/octet-stream");
                    //httpClient.DefaultRequestHeaders.Add("Accept", "*/*");

                    //httpClient.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, br");
                    //httpClient.DefaultRequestHeaders.Add("Connection", "keep-alive");

                    // Send post request
                    HttpResponseMessage response = await httpClient.PostAsync(requestUri, form);

                    // Check response
                    response.EnsureSuccessStatusCode();
                }
            }
        }
    }
    catch
    {
        MessageBox.Show("Try sending data again and check your connection!");
    }
}

我添加了

RequestVerificationToken

手动发送给我的邮递员 post 命令。另外，我将其添加到 C# 中的 post 命令中。虽然Postman命令成功了，但是C# post命令不起作用。

正如您根据我在客户端代码中的注释所看到的，我尝试了很多选项。但他们都失败了。

C# 中服务器对客户端的响应：

    {StatusCode: 400, ReasonPhrase: 'Bad Request', Version: 1.1, 
    Content: System.Net.Http.StreamContent, Headers:
    {
        Connection: close
        Transfer-Encoding: chunked
        Date: Wed, 08 May 2024 07:39:44 GMT
        Server: Kestrel
        Content-Type: text/plain; charset=utf-8
    }}

Answer 1

首先，您的客户端示例代码没有在表单中添加文件内容，而仅在表单中添加标题，因此您将向服务器发送一个空表单并当然会收到错误。 （或者你可以删除评论）

form.Add(fileContent, "file", filename);

并且您可以尝试在文件内容而不是表单中添加标头。如果它不起作用，那么这里是一个由 WebApplication 和 HttpClient 完成的上传文件示例。

服务器代码

var app = WebApplication.CreateBuilder(args).Build();
app.MapPost("/upload2", (HttpContext ctx) =>
{
    return ctx.Request.Form.Files.First().FileName;
});
app.Run();

客户端代码

var filePath = "./test.xlsx";
var fileName = "test.xlsx";
var requestUri = "http://localhost:5000/upload2";
using var httpClient = new HttpClient();
using var form = new MultipartFormDataContent {
    {
        new ByteArrayContent(File.ReadAllBytes(filePath)), "file", fileName
    }
};
Console.WriteLine(httpClient.PostAsync(requestUri, form).Result);