WebAPI 文件下载

Question

我需要创建一个下载文件的 WebAPI 方法。该文件正在正确下载，但下载似乎仍然停留在客户端浏览器中几乎 100% 的速度（即，尽管文件已经下载并且可以打开，但它不会终止）。在终止之前保持这种状态几分钟。问题可能是什么？以下是一些复制我的问题的测试代码

[HttpGet]
public HttpResponseMessage GetFile()
{
    string fileName = @"c:\temp\test.zip";

    MemoryStream responseStream = new MemoryStream();
    using (FileStream source = File.Open(fileName, FileMode.Open))
        source.CopyTo(responseStream);

    HttpResponseMessage response = new HttpResponseMessage();
    response.Content = new StreamContent(responseStream);
    response.StatusCode = HttpStatusCode.OK;
    response.Content.Headers.ContentType = new MediaTypeHeaderValue(ContentTypeHelper.Instance.GetFileContentType(fileName));
    response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
    response.Content.Headers.ContentDisposition.FileName = fileName;
    response.Content.Headers.ContentLength = responseStream.Length;
    return response;
}

Answer 1

看来您需要在复制后倒带 MemoryStream：

MemoryStream responseStream = new MemoryStream();
using (FileStream source = File.Open(fileName, FileMode.Open))
    source.CopyTo(responseStream);
responseStream.Seek(0, SeekOrigin.Begin);