问题
我想在我的ASP中返回一个文件。Net Web API控制器，但我所有的方法返回HttpResponseMessage作为JSON。
目前为止的代码
public async Task<HttpResponseMessage> DownloadAsync(string id)
{
var response = new HttpResponseMessage(HttpStatusCode.OK);
response.Content = new StreamContent({{__insert_stream_here__}});
response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
return response;
}
当我在浏览器中调用这个端点时，Web API将HttpResponseMessage返回为JSON，并将HTTP内容报头设置为application/ JSON。
当前回答
你可以用这些方法返回FileResult:
1:返回FileStreamResult
[HttpGet("get-file-stream/{id}"]
public async Task<FileStreamResult> DownloadAsync(string id)
{
var fileName="myfileName.txt";
var mimeType="application/....";
Stream stream = await GetFileStreamById(id);
return new FileStreamResult(stream, mimeType)
{
FileDownloadName = fileName
};
}
2:返回FileContentResult
[HttpGet("get-file-content/{id}"]
public async Task<FileContentResult> DownloadAsync(string id)
{
var fileName="myfileName.txt";
var mimeType="application/....";
byte[] fileBytes = await GetFileBytesById(id);
return new FileContentResult(fileBytes, mimeType)
{
FileDownloadName = fileName
};
}
其他回答
如果这是ASP.net-Core，那么你混合了web API版本。让动作返回一个派生的IActionResult，因为在当前代码中，框架将HttpResponseMessage作为模型处理。
[Route("api/[controller]")]
public class DownloadController : Controller {
//GET api/download/12345abc
[HttpGet("{id}")]
public async Task<IActionResult> Download(string id) {
Stream stream = await {{__get_stream_based_on_id_here__}}
if(stream == null)
return NotFound(); // returns a NotFoundResult with Status404NotFound response.
return File(stream, "application/octet-stream", "{{filename.ext}}"); // returns a FileStreamResult
}
}
注意:
当响应完成时，框架将处理在这种情况下使用的流。如果使用using语句，流将在响应发送之前被处理，并导致异常或损坏响应。
FileStreamResult为我工作。文件不是IActionResult。我不知道该怎么做。
添加 builder.Services.AddSingleton (); 在 Program.cs
[HttpGet("{fileId}")]
public ActionResult GetFile(string fileId)
{
string pathToFile = "test.rar";
if (!System.IO.File.Exists(pathToFile))
{
return NotFound();
}
if(!_fileExtensionContentTypeProvider.TryGetContentType(pathToFile,
out var ContentType))
{
ContentType = "application/octet-stream";
}
var byets=System.IO.File.ReadAllBytes(pathToFile);
return File(byets, ContentType, Path.GetFileName(pathToFile));
}
}
你可以用这些方法返回FileResult:
1:返回FileStreamResult
[HttpGet("get-file-stream/{id}"]
public async Task<FileStreamResult> DownloadAsync(string id)
{
var fileName="myfileName.txt";
var mimeType="application/....";
Stream stream = await GetFileStreamById(id);
return new FileStreamResult(stream, mimeType)
{
FileDownloadName = fileName
};
}
2:返回FileContentResult
[HttpGet("get-file-content/{id}"]
public async Task<FileContentResult> DownloadAsync(string id)
{
var fileName="myfileName.txt";
var mimeType="application/....";
byte[] fileBytes = await GetFileBytesById(id);
return new FileContentResult(fileBytes, mimeType)
{
FileDownloadName = fileName
};
}
下面是一个简单的文件流示例:
using System.IO;
using Microsoft.AspNetCore.Mvc;
[HttpGet("{id}")]
public async Task<FileStreamResult> Download(int id)
{
var path = "<Get the file path using the ID>";
var stream = File.OpenRead(path);
return new FileStreamResult(stream, "application/octet-stream");
}
注意:
请确保使用来自Microsoft.AspNetCore.Mvc而不是System.Web.Mvc的FileStreamResult。
