c# – 在ASP.NET Core中设置app.UseFileServer后获取PhysicalPath

我有虚拟目录指向IIS中的一些文件服务器.我了解到ASP.NET Core无法“看到”IIS中的虚拟目录,因为它在Kestral上运行.

我被告知解决方法是使用app.UseFileServer：

app.UseFileServer(new FileServerOptions
{
    FileProvider = new PhysicalFileProvider(@"\\server\path"),
    RequestPath = new PathString("/MyPath"),
    EnableDirectoryBrowsing = true
});

我设置了它,当我在浏览器地址栏中键入/ MyPath时它可以工作.
但是,我希望能够在控制器中获得物理路径.

就像是：

//Server.Map path no longer exists in ASP.NET Core...
var filePath = Server.MapPath("/MyPath");
var fileName = "MyFile.txt";
System.IO.File.OpenRead(Path.Combine(filePath , fileName));

有没有办法通过在app.UseFileServer中提供RequestPath I设置来获取物理路径？

解决方法:

此问题的核心是访问控制器中正确的IFileProvider(指向目录的物理路径).

您可以通过在自定义服务中配置这些路径来实现此目的,以便您可以在任何位置访问它们：

>在Configure()方法中设置UseFileServer
>在您的控制器等

我有一些代码来演示如何解决这个问题：

服务和便利方法

首先,创建一个自定义服务,该服务将保存可由UseFileServer()或您的控制器访问的FileServerOptions.我选择了它们的列表,因此您可以添加多个路径.

public interface IFileServerProvider
{
    /// <summary>
    /// Contains a list of FileServer options, a combination of virtual + physical paths we can access at any time
    /// </summary>
    IList<FileServerOptions> FileServerOptionsCollection { get; }

    /// <summary>
    /// Gets the IFileProvider to access a physical location by using its virtual path
    /// </summary>
    IFileProvider GetProvider(string virtualPath);
}

/// <summary>
/// Implements IFileServerProvider in a very simple way, for demonstration only
/// </summary>
public class FileServerProvider : IFileServerProvider
{
    public FileServerProvider(IList<FileServerOptions> fileServerOptions)
    {
        FileServerOptionsCollection = fileServerOptions;
    }

    public IList<FileServerOptions> FileServerOptionsCollection { get; }

    public IFileProvider GetProvider(string virtualPath)
    {
        var options = FileServerOptionsCollection.FirstOrDefault(e => e.RequestPath == virtualPath);
        if (options != null)
            return options.FileProvider;

        throw new FileNotFoundException($"virtual path {virtualPath} is not registered in the fileserver provider");
    }
}

然后,为方便起见,您还可以添加一个Extension方法,该方法将使用上述服务中的选项调用UseFileServer中间件：

/// <summary>
/// Wrapper for UseFileServer to easily use the FileServerOptions registered in the IFileServerProvider
/// </summary>
public static class FileServerProviderExtensions
{
    public static IApplicationBuilder UseFileServerProvider(this IApplicationBuilder application, IFileServerProvider fileServerprovider)
    {
        foreach (var option in fileServerprovider.FileServerOptionsCollection)
        {
            application.UseFileServer(option);
        }
        return application;
    }
}

启动方法

现在,您只需要使用您选择的路径(1)注册IFileServerProvider,并将其移交给方便方法以实际使用它们(2).

(1)首先,使用您选择的路径将IFileServerProvider注册为Singleton服务：

public void ConfigureServices(IServiceCollection services)
{
    //Add our IFileServerProvider implementation as a singleton
    services.AddSingleton<IFileServerProvider>(new FileServerProvider(
        new List<FileServerOptions>
        {
            new FileServerOptions
            {
                FileProvider = new PhysicalFileProvider(@"D:\\somepath"),
                RequestPath = new PathString("/OtherPath"),
                EnableDirectoryBrowsing = true
            },
            new FileServerOptions
            {
                FileProvider = new PhysicalFileProvider(@"\\server\path"),
                RequestPath = new PathString("/MyPath"),
                EnableDirectoryBrowsing = true
            }
        }));

    // Add framework services.
    services.AddMvc();
}

(2)然后通过调用之前创建的扩展方法实际在UseFileServer中使用它们.请注意Configure方法中的额外参数IFileServerProvider fileServerprovider：

// Note: accessing the IFileServerProvider implemantion here by adding it 
// in the arguments list!
public void Configure(IApplicationBuilder app, IFileServerProvider fileServerprovider)
{
    //call convenience method which adds our FileServerOptions from 
    // the IFileServerProvider service
    app.UseFileServerProvider(fileServerprovider);

    app.UseMvc(routes =>
    {
        routes.MapRoute(
            name: "default",
            template: "{controller=Home}/{action=Index}/{id?}");
    });
}

用法

现在,当您浏览到路径/ MyPath或/ OtherPath时,您应该像以前一样获得目录列表.

但是,因为我们在服务中拥有整洁的东西,所以现在可以更容易地在Controller中以编程方式访问这些路径：

public class HomeController : Controller
{
    private IFileServerProvider _fileServerProvider;

    public HomeController(IFileServerProvider fileServerProvider)
    {
        _fileServerProvider = fileServerProvider;
    }

    public IActionResult Index()
    {
        var fileProvider = _fileServerProvider.GetProvider("/MyPath");
        var fileInfo = fileProvider.GetFileInfo("MyFile.txt");
        using (var stream = System.IO.File.OpenRead(fileInfo.PhysicalPath))
        {
            string contents = new StreamReader(stream).ReadToEnd();
        }
        return View();
    }
}

这段代码可能是用更抽象,更充分命名的版本编写的,但它演示了一个解决问题的工作方案.

标签：c,asp-net,asp-net-core,asp-net-core-mvc,static-files
来源： https://codeday.me/bug/20190627/1307768.html