将文件写到响应后，有没有办法完成回发？ [英] Is there a way to complete the post back after writing out a file to the Response?

问题描述

我有一个按钮，当单击该按钮时，将生成PDF并将其写到响应中。

I have a button that when clicked, will generate a PDF and write it out to the response.

这是代码的基本结构：

try
{
    using(Stream stream = generatePdf())
    {
       var file = createFile(stream);
       file.Transmit(HttpContext.Current.Response);
    }
}
catch (Exception ex)
{
    // Handle exception
    // Display Error Message
}

传输方法包含以下代码：

The transmit method contains the following code:

response.AddHeader("Content-Disposition", String.Format("attachment; filename={0}", filename));
response.AddHeader("Content-Length", bytes.Length.ToString());
response.ContentType = "application/octet-stream";
response.BinaryWrite(bytes);

下载文件可以正常工作，只是不能完成回发。

Downloading the file works fine, except that it doesn't complete the postback.

如果我在 file.Transmit 之上抛出异常，错误处理将正常工作，并且我会看到消息显示在我的浏览器。但是，如果 file.Transmit 之后存在异常，则什么也不会发生。用户保存/打开pdf，并且页面不会重新加载。

If I were to throw an exception above file.Transmit, the error handling would work properly and I would see the message get displayed in my browser. However, if there is an exception after the file.Transmit then nothing happens. The user saves/opens the pdf and the page does not reload.

我该如何做到使回发始终完成，这样我就可以向

How can I make it so that the postback always completes, that way I can display an appropriate message to the user?

推荐答案

听起来您正在尝试使响应包含两部分：页面和 PDF。你不能那样做。通常，下载页面在到达页面后会作为一个单独的请求开始下载（我相信是通过JavaScript），并带有直接链接，以防JavaScript无法正常工作。

It sounds like you're trying to make the response contain two parts: the page and the PDF. You can't do that. Typically download pages start a download as a separate request when you've gone to them (via JavaScript, I believe), with a direct link just in case the JavaScript doesn't work.

任何一个HTTP请求只能有一个响应。

Any one HTTP request can only have one response.

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