西里尔文文件名上传Azure Blob容器触发System.AggregateException的解决办法

问题原因 #

经排查，异常由原文件名中的西里尔文存入Blob元数据引发。Azure Blob存储的元数据字段默认要求值为ASCII兼容字符，直接存入非ASCII字符（如西里尔文）会触发编码错误，最终抛出System.AggregateException。

解决方法 #

1. 对元数据中的非ASCII文件名编码 #

将原文件名进行URL编码后存入元数据，读取时再解码，确保符合Azure元数据的字符规范。

修改代码中元数据初始化部分：

// 需引用 System.Net 命名空间
var metadata = new Dictionary<string, string>
{
    { "Email", userEmail },
    { "UserFileName", System.Net.WebUtility.UrlEncode(file.FileName) }
};

后续读取原文件名时解码：

string originalFileName = System.Net.WebUtility.UrlDecode(blobClient.GetProperties().Value.Metadata["UserFileName"]);

2. 捕获内部异常精准定位（调试用） #

展开AggregateException的内部异常，能直接获取错误根源：

catch (AggregateException ex)
{
    var innerErrors = ex.Flatten().InnerExceptions.Select(e => e.Message);
    return StatusCode(500, $"上传错误详情：{string.Join(" | ", innerErrors)}");
}

3. 验证扩展名提取（可选） #

若扩展名包含西里尔文（如.документ），可添加日志确认Path.GetExtension是否正确提取：

string extension = Path.GetExtension(file.FileName);
Console.WriteLine($"提取的扩展名：{extension}");

完整修改后代码 #

using Azure.Storage.Blobs;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Azure.Storage.Blobs.Models;
using System.IO;
using System;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Net; // 添加命名空间

namespace DocxSender.API.Controllers
{
    [ApiController]
    [Route("api/upload")]
    public class UploadController : Controller
    {
        private readonly IConfiguration _config;

        public UploadController(IConfiguration config)
        {
            _config = config;
        }

        [HttpPost]
        public async Task<IActionResult> Upload([FromForm] IFormFile file, [FromForm] string userEmail)
        {
            string containerConnectionString = _config.GetValue<string>("ConnectionString");
            string blobName = _config.GetValue<string>("BlobName");

            string fileName = Guid.NewGuid().ToString();
            string extension = Path.GetExtension(file.FileName);

            BlobServiceClient blobServiceClient = new BlobServiceClient(containerConnectionString);
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(blobName);
            BlobClient blobClient = containerClient.GetBlobClient(fileName + extension);

            var metadata = new Dictionary<string, string>
            {
                { "Email", userEmail },
                { "UserFileName", WebUtility.UrlEncode(file.FileName) } // 编码原文件名
            };

            try
            {
                await blobClient.UploadAsync(file.OpenReadStream(), new BlobUploadOptions()
                {
                    Metadata = metadata
                });

                return Ok();
            }
            catch (AggregateException ex)
            {
                var innerErrors = ex.Flatten().InnerExceptions.Select(e => e.Message);
                return StatusCode(500, $"上传错误：{string.Join(" | ", innerErrors)}");
            }
            catch (Exception ex)
            {
                return StatusCode(500, $"上传文件出错：{ex.Message}");
            }
        }
    }
}

内容的提问来源于stack exchange，提问作者swaggoo