使用ASP.NET Core将PDF返回到浏览器 [英] Return PDF to the Browser using ASP.NET Core

问题描述

我在ASP.Net核心中创建了Wep API以返回PDF.这是我的代码:

I created the Wep API in ASP.Net core to return the PDF. Here is my code:

public HttpResponseMessage Get(int id)
{
    var response = new HttpResponseMessage(System.Net.HttpStatusCode.OK);           
    var stream = new System.IO.FileStream(@"C:\Users\shoba_eswar\Documents\REquest.pdf", System.IO.FileMode.Open);
    response.Content = new StreamContent(stream);
    response.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
    response.Content.Headers.ContentDisposition.FileName = "NewTab";
    response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/pdf");
    return response;
}

但是它仅返回JSON响应:

But it returns only the JSON response:

{
   "version":{
      "major":1,
      "minor":1,
      "build":-1,
      "revision":-1,
      "majorRevision":-1,
      "minorRevision":-1
   },
   "content":{
      "headers":[
         {
            "key":"Content-Disposition",
            "value":[
               "attachment; filename=NewTab"
            ]
         },
         {
            "key":"Content-Type",
            "value":[
               "application/pdf"
            ]
         }
      ]
   },
   "statusCode":200,
   "reasonPhrase":"OK",
   "headers":[

   ],
   "requestMessage":null,
   "isSuccessStatusCode":true
}

我在这里做错什么了吗?

Am I doing anything wrong here?

推荐答案

如

As explained in ASP.NET Core HTTPRequestMessage returns strange JSON message, ASP.NET Core does not support returning an HttpResponseMessage (what package did you install to get access to that type?).

因此，串行器只需将HttpResponseMessage的所有公共属性写入输出中，就如同将其与任何其他不受支持的响应类型一样.

Because of this, the serializer is simply writing all public properties of the HttpResponseMessage to the output, as it would with any other unsupported response type.

要支持自定义响应，您必须返回一个IActionResult实现类型.有很多这样的.对于您的情况，我将查看

To support custom responses, you must return an IActionResult-implementing type. There's plenty of those. In your case, I'd look into the FileStreamResult:

public IActionResult Get(int id)
{
    var stream = new FileStream(@"path\to\file", FileMode.Open);
    return new FileStreamResult(stream, "application/pdf");     
}

或者只需使用 PhysicalFileResult ，为您处理流:

Or simply use a PhysicalFileResult, where the stream is handled for you:

public IActionResult Get(int id)
{
    return new PhysicalFileResult(@"path\to\file", "application/pdf");
}

当然，可以使用诸如Controller.File()的辅助方法来简化所有这些操作:

Of course all of this can be simplified using helper methods, such as Controller.File():

public IActionResult Get(int id)
{
    var stream = new FileStream(@"path\to\file", FileMode.Open);
    return File(stream, "application/pdf", "FileDownloadName.ext");
}

这只是抽象了FileContentResult或FileStreamResult的创建(对于此重载，后者).

This simply abstracts the creation of a FileContentResult or FileStreamResult (for this overload, the latter).

或者，如果您要转换较旧的MVC或Web API应用程序，并且不想一次转换所有代码，请添加对 ResponseMessageResult :

Or if you're converting an older MVC or Web API application and don't want to convert all your code at once, add a reference to WebApiCompatShim (NuGet) and wrap your current code in a ResponseMessageResult:

public IActionResult Get(int id)
{
    var response = new HttpResponseMessage(HttpStatusCode.OK);           
    var stream = ...
    response.Content...

    return new ResponseMessageResult(response);
}

如果您不想使用return File(fileName, contentType, fileDownloadName)，则FileStreamResult不支持从构造函数或通过属性设置content-disposition标头.

If you don't want to use return File(fileName, contentType, fileDownloadName), then the FileStreamResult doesn't support setting the content-disposition header from the constructor or through properties.

在这种情况下，您必须先将该响应标头添加到响应中，然后再返回文件结果:

In that case you'll have to add that response header to the response yourself before returning the file result:

var contentDisposition = new ContentDispositionHeaderValue("attachment");
contentDisposition.SetHttpFileName("foo.txt");
Response.Headers[HeaderNames.ContentDisposition] = contentDisposition.ToString();

这篇关于使用ASP.NET Core将PDF返回到浏览器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！