我在ASP.Net核心中创建了Wep API以返回PDF.这是我的代码：
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;
}
但它只返回JSON响应：
{
"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
}
我在这做错了吗？
解决方法
如
ASP.NET Core HTTPRequestMessage returns strange JSON message中所述,ASP.NET Core不支持返回HttpResponseMessage(您安装了哪些软件包以访问该类型？).
因此,序列化程序只是将HttpResponseMessage的所有公共属性写入输出,就像使用任何其他不受支持的响应类型一样.
要支持自定义响应,您必须返回IActionResult实现类型.有plenty of those.在你的情况下,我会调查FileStreamResult：
public IActionResult Get(int id)
{
using (var stream = new FileStream(@"path\to\file",FileMode.Open))
{
return new FileStreamResult(stream,"application/pdf");
}
}
或者只需使用PhysicalFileResult,即可为您处理流：
public IActionResult Get(int id)
{
return new FileStreamResult(@"path\to\file","application/pdf");
}
当然所有这些都可以使用辅助方法简化,例如Controller.File()：
public IActionResult Get(int id)
{
using (var stream = new FileStream(@"path\to\file",FileMode.Open))
{
return File(stream,"application/pdf","FileDownloadName.ext");
}
}
这简单地抽象了FileContentResult或FileStreamResult的创建(对于这个重载,后者).
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WebApiCompatShim (NuGet)的引用并将当前代码包装在ResponseMessageResult中：
public IActionResult Get(int id)
{
var response = new HttpResponseMessage(HttpStatusCode.OK);
var stream = ...
response.Content...
return new ResponseMessageResult(response);
}
如果您不想使用返回文件(fileName,contentType,fileDownloadName),则FileStreamResult不支持从构造函数或通过属性设置content-disposition标头.
在这种情况下,您必须在返回文件结果之前自己将响应标头添加到响应中：
var contentDisposition = new ContentDispositionHeaderValue("attachment");
contentDisposition.SetHttpFileName("foo.txt");
Response.Headers[HeaderNames.ContentDisposition] = contentDisposition.ToString();
