Question

也许我不理解VirtualFileResult是什么，但我不确定为什么文件存在时会抛出FileNotFoundException。这是代码：

if (System.IO.File.Exists(fileName))
{
    FileInfo info = new FileInfo(fileName);

    return File(fileName, FileUtility.GetContentType(fileName), info.Name);
}

（编辑：FileUtility.GetContentType（正确）返回文件的Mime类型，在我的情况下是"application/pdf"。）

以下是我得到的异常:(我删除了文件路径）

System.IO.FileNotFoundException: Could not find file: [file path removed]
File name: '[file path removed]'
   at Microsoft.AspNet.Mvc.VirtualFileResult.<WriteFileAsync>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Mvc.Controllers.FilterActionInvoker.<InvokeResultAsync>d__56.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Mvc.Controllers.FilterActionInvoker.<InvokeResultFilterAsync>d__55.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.AspNet.Mvc.Controllers.FilterActionInvoker.<InvokeAllResultFiltersAsync>d__54.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Mvc.Controllers.FilterActionInvoker.<InvokeResourceFilterAsync>d__49.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.AspNet.Mvc.Controllers.FilterActionInvoker.<InvokeAsync>d__44.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Mvc.Infrastructure.MvcRouteHandler.<RouteAsync>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Routing.Template.TemplateRoute.<RouteAsync>d__27.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Routing.RouteCollection.<RouteAsync>d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Builder.RouterMiddleware.<Invoke>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.IISPlatformHandler.IISPlatformHandlerMiddleware.<Invoke>d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Diagnostics.StatusCodePagesMiddleware.<Invoke>d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.AspNet.Diagnostics.DeveloperExceptionPageMiddleware.<Invoke>d__7.MoveNext()

即使对文件是否存在进行了明确的检查，它似乎也在喋喋不休。我也可以手动确认文件存在。

也许我不理解VirtualFileResult是什么（File方法返回此）。在文档here上，它并没有真正描述它是什么。

我正在使用ASP.NET 5 RC1。

Answer 1

VirtualFileResult类需要在其构造函数中指向文件的虚拟路径这意味着您需要提供相对于wwwroot文件夹的路径，因为它使用HostingEnvironment＆＃39; WebRootFileProvider。

    private IFileProvider GetFileProvider(IServiceProvider requestServices)
    {
        if (FileProvider != null)
        {
            return FileProvider;
        }

        var hostingEnvironment = requestServices.GetService<IHostingEnvironment>();
        FileProvider = hostingEnvironment.WebRootFileProvider;

        return FileProvider;
    }
}

检查github

上的代码

Answer 2

运气不好（＆＃34; index.html＆＃34;）或文件（＆＃34;〜/ index.html＆＃34;），Virtualfileresult会抛出NotFound。

我的解决方案是使用Microsoft.AspNetCore.Mvc.ControllerBase 方法File（Stream fileStream ...）：

public virtual FileStreamResult File(Stream fileStream, 
       string contentType, string fileDownloadName);

索引控制器示例：

 using System.IO;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Logging;

 public class IndexController : Controller
 {
    ILoggerFactory Logger;

    public IndexController(ILoggerFactory loggerFactory)
    {
        Logger = loggerFactory;
    }

    static string sep = Path.DirectorySeparatorChar.ToString();

    [HttpGet("/index")]
    [HttpGet("/")]
    public IActionResult Index()
    {
        var log = Logger.CreateLogger("trace");

        var path = $"{Startup.RootPath}{sep}index.html";
        log.LogWarning(path);
        Stream fileStream  = new System.IO.FileStream(path, FileMode.Open);

        return File(fileStream, "text/html");
    }
}

// AspnetCore version 1.1.1 :
// <TargetFramework>netcoreapp1.1</TargetFramework>
// <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />

Answer 3

您要查找的方法是PhysicalFile()：

return PhysicalFile(fileName, FileUtility.GetContentType(fileName), info.Name);

当心，请勿为此使用呼叫者提供的路径。

Answer 4

您的VirtualFileResult必须是应用程序的wwwroot 的相对路径。

return File("~/foo.js","text/javascript")

将指向wwwroot / foo.js

文件存在时找不到VirtualFileResult文件

4 个答案: