通过MS Graph API上传Drive文件遇资源未找到问题求助

尝试通过MS Graph API上传小于4MB的.xlsx文件到指定Drive位置，执行代码时出现错误：Resource not found for the segment Oks

原代码 #

public static string DecodeData(string encodedData)
{
    byte[] encodedDataAsBytes = System.Convert.FromBase64String(encodedData);
    string returnValue = System.Text.ASCIIEncoding.ASCII.GetString(encodedDataAsBytes);
    return returnValue;
}
// Upload files to SharePoint
public void SharePointUploadDriveItems(string accessToken)
{
    var httpClient = new HttpClient();

    try
    {
        string path = @"C:\\StockLevelReportLocation\\New Files\\TestFileUpload.xlsx";
        byte[] filebytes = System.IO.File.ReadAllBytes(path);

        using (var client = new HttpClient())
        {
            string fileName = "TestFileToUpload.txt";

            using (var request = new HttpRequestMessage(HttpMethod.Put, "https://graph.microsoft.com/v1.0/drives/root/Oks/Stock Report/TestFileUpload.xlsx/content"))
            {
                request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
                request.Headers.Add("Accept", "application/json;odata.metadata=verbose");
                request.Content = new StringContent(DecodeData(Convert.ToBase64String(filebytes)), System.Text.Encoding.ASCII, "text/plain");
                var driveItemsResponse = httpClient.SendAsync(request).Result;
                var driveItemsResponseContent = driveItemsResponse.Content.ReadAsStringAsync().Result;
            }
        }
    }
    catch (Exception ex)
    {
        throw new Exception(ex.ToString());
    }
}

1. API路径格式错误 #

Graph API访问Drive文件的标准语法要求drives/root后使用:/路径:/content的格式，原URL缺少路径前后的:/，导致API无法正确识别Oks这个路径段，触发资源找不到的错误。

正确的请求URL应为：
https://graph.microsoft.com/v1.0/drives/root:/Oks/Stock Report/TestFileUpload.xlsx:/content

2. 文件内容处理逻辑错误 #

• DecodeData方法完全多余，且用ASCII编码处理二进制文件（xlsx属于二进制格式）会丢失字节，破坏文件结构。直接使用文件字节数组作为请求内容即可，无需Base64转码再解码。
• 请求内容的MediaType设置错误，xlsx文件对应的MIME类型是application/vnd.openxmlformats-officedocument.spreadsheetml.sheet，而非text/plain。

3. 代码优化点 #

• 避免用.Result同步调用异步方法，易引发死锁，改用await实现异步流程。
• 重复创建HttpClient会导致资源泄漏，建议复用单例实例。

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

// Upload files to SharePoint
public async Task SharePointUploadDriveItemsAsync(string accessToken)
{
    // 建议全局复用HttpClient实例，避免重复创建
    using var client = new HttpClient();

    try
    {
        string filePath = @"C:\StockLevelReportLocation\New Files\TestFileUpload.xlsx";
        byte[] fileBytes = File.ReadAllBytes(filePath);
        string fileName = Path.GetFileName(filePath);

        // 修正后的Graph API请求地址
        string requestUri = "https://graph.microsoft.com/v1.0/drives/root:/Oks/Stock Report/TestFileUpload.xlsx:/content";
        
        using var request = new HttpRequestMessage(HttpMethod.Put, requestUri);
        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
        request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        
        // 直接传入文件字节数组，设置正确的MIME类型
        request.Content = new ByteArrayContent(fileBytes);
        request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        
        HttpResponseMessage response = await client.SendAsync(request);
        response.EnsureSuccessStatusCode(); // 主动抛出HTTP状态错误
        string responseContent = await response.Content.ReadAsStringAsync();
    }
    catch (Exception ex)
    {
        throw new Exception($"文件上传失败: {ex.Message}", ex);
    }
}

• 确认Oks文件夹确实存在于Drive根目录，路径名称无拼写错误（Graph API路径区分大小写）。
• 确保accessToken拥有Files.ReadWrite（个人Drive）或Sites.ReadWrite.All（SharePoint站点Drive）的权限。

内容的提问来源于stack exchange，提问作者KSampath