试图用流一个asp.net PDF文件是生产和QUOT;损坏的文件＆QUOT; [英] Trying to stream a PDF file with asp.net is producing a "damaged file"

问题描述

在我的asp.net web应用程序一个我需要隐藏被送达给用户一个PDF文件的位置。

于是，我写了从一个CMS系统上的位置检索其二进制内容，然后一个方法刷新字节数组Web用户。

我下载流时获得，遗憾的是，一个错误：无法打开该文件，因为它是damadged（或类似的东西，打开Adobe Reader中的文件时）

问题1：我究竟做错了什么？
问题2：我可以下载使用这种方法大文件

 私人无效StreamFile（的iItem documentItem）
    {
        // CMS厂商特定的API
        BinaryContent itemBinaryContent = documentItem.getBinaryContent（）;
        //普通老式.NET
        流FILESTREAM = itemBinaryContent.getContentStream（）;
        变种LEN = itemBinaryContent.getContentLength（）;
        SendStream（FILESTREAM，LEN，itemBinaryContent.getContentType（））;
    }    私人无效SendStream（流流，诠释contentLen，字符串的contentType）
    {
        Response.ClearContent（）;
        Response.ContentType = contentType中;
        Response.AppendHeader（内容处置的String.Format（内联;文件名= file.pdf））;
        Response.AppendHeader（内容长度，contentLen.ToString（））;
        VAR字节=新的字节[contentLen]
        stream.Read（字节，0，c​​ontentLen）;
        stream.Close（）;
        Response.BinaryWrite（字节）;
        Response.Flush（）;
    }
 

解决方案

下面是我使用的方法。这回传附件，因此IE产生打开/保存对话框。我也碰巧知道该文件将不大于1M，所以我敢肯定有一个更清洁的方式来做到这一点。

我和PDF文件类似的问题，我意识到，我绝对必须使用二进制流和的ReadBytes。凡是用绳子把事情搞糟了。

 流流= GetStream（）; //假设你有一个做到这一点的方法。
BinaryReader读卡器=新BinaryReader（流）;HTT presponse响应= HttpContext.Current.Response;
response.ContentType =应用程序/ PDF
response.AddHeader（内容处置，附件;文件名= file.pdf）;
response.ClearContent（）;
response.OutputStream.Write（reader.ReadBytes（1000000），0，1000000）;//结束由页处理器prevent进一步工作的响应。
到Response.End（）;
 

In one of my asp.net web applications I need to hide the location of a pdf file being served to the users.

Thus, I am writing a method that retrieves its binary content from its location on a CMS system and then flushes a byte array to the web user.

I'm getting, unfortunately, an error when downloading the stream: "Could not open the file because it is damadged" (or something similar to that, when opening the file in adobe reader).

Question 1: what am I doing wrong? Question 2: can I download large files using this approach?

    private void StreamFile(IItem documentItem)
    {
        //CMS vendor specific API
        BinaryContent itemBinaryContent = documentItem.getBinaryContent();
        //Plain old .NET
        Stream fileStream = itemBinaryContent.getContentStream();
        var len = itemBinaryContent.getContentLength();
        SendStream(fileStream, len, itemBinaryContent.getContentType());
    }

    private void SendStream(Stream stream, int contentLen, string contentType)
    {
        Response.ClearContent();
        Response.ContentType = contentType;
        Response.AppendHeader("content-Disposition", string.Format("inline;filename=file.pdf"));
        Response.AppendHeader("content-length", contentLen.ToString());
        var bytes = new byte[contentLen];
        stream.Read(bytes, 0, contentLen);
        stream.Close();
        Response.BinaryWrite(bytes);
        Response.Flush();
    }

解决方案

Here is a method I use. This passes back an attachment, so IE produces an Open/Save dialog. I also happen to know that the files will not be larger than 1M, so I'm sure there's a cleaner way to do this.

I had a similar problem with PDFs, and I realized that I absolutely had to use Binary streams and ReadBytes. Anything with strings messed it up.

Stream stream = GetStream(); // Assuming you have a method that does this.
BinaryReader reader = new BinaryReader(stream);

HttpResponse response = HttpContext.Current.Response;
response.ContentType = "application/pdf";
response.AddHeader("Content-Disposition", "attachment; filename=file.pdf");
response.ClearContent();
response.OutputStream.Write(reader.ReadBytes(1000000), 0, 1000000);

// End the response to prevent further work by the page processor.
response.End();

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