Question

如何在 Server.MapPath

中获取ASP网络核心替代方式的绝对路径

我尝试使用 IHostingEnvironment ，但它没有给出正确的结果。

IHostingEnvironment env = new HostingEnvironment();
var str1 = env.ContentRootPath; // Null
var str2 = env.WebRootPath; // Null, both doesn't give any result

我在 wwwroot 文件夹中有一个图像文件（Sample.PNG）我需要获得这个绝对路径。

Answer 1

将IHostingEnvironment作为依赖项注入依赖类。该框架将为您填充

public class HomeController : Controller {
    private IHostingEnvironment _hostingEnvironment;

    public HomeController(IHostingEnvironment environment) {
        _hostingEnvironment = environment;
    }

    [HttpGet]
    public IActionResult Get() {
        var path = Path.Combine(_hostingEnvironment.WebRootPath, "Sample.PNG");
        return View();
    }
}

您可以更进一步，创建自己的路径提供程序服务抽象和实现。

public interface IPathProvider {
    string MapPath(string path);
}

public class PathProvider : IPathProvider {
    private IHostingEnvironment _hostingEnvironment;

    public PathProvider(IHostingEnvironment environment) {
        _hostingEnvironment = environment;
    }

    public string MapPath(string path) {
        var filePath = Path.Combine(_hostingEnvironment.WebRootPath, path);
        return filePath;
    }
}

将IPathProvider注入依赖类。

public class HomeController : Controller {
    private IPathProvider pathProvider;

    public HomeController(IPathProvider pathProvider) {
        this.pathProvider = pathProvider;
    }

    [HttpGet]
    public IActionResult Get() {
        var path = pathProvider.MapPath("Sample.PNG");
        return View();
    }
}

确保使用DI容器注册服务

services.AddSingleton<IPathProvider, PathProvider>();

Answer 2

*入侵* 不推荐，但仅供参考，您可以使用 var abs = Path.GetFullPath("~/Content/Images/Sample.PNG").Replace("~\\","");

首选上述DI / Service方法，但是如果您处于非DI情况（例如，以Activator实例化的类），则可以使用。

Answer 3

更好的解决方案是使用x方法。

IFileProvider.GetFileInfo()

您必须注册public IActionResult ResizeCat([FromServices] IFileProvider fileProvider) { // get absolute path (equivalent to MapPath) string absolutePath = fileProvider.GetFileInfo("/assets/images/cat.jpg").PhysicalPath; ... } like this to be able to access it through DI：

IFileProvider

如您所见，这种逻辑（文件的来源）可能会变得非常复杂，但是如果更改，代码不会中断。

如果您有特殊的逻辑，则可以使用// This method gets called by the runtime. Use this method to add services to the container. public void ConfigureServices(IServiceCollection services) { // Add framework services. services.AddMvc(); var physicalProvider = _hostingEnvironment.ContentRootFileProvider; var embeddedProvider = new EmbeddedFileProvider(Assembly.GetEntryAssembly()); var compositeProvider = new CompositeFileProvider(physicalProvider, embeddedProvider); // choose one provider to use for the app and register it //services.AddSingleton<IFileProvider>(physicalProvider); //services.AddSingleton<IFileProvider>(embeddedProvider); services.AddSingleton<IFileProvider>(compositeProvider); }创建自定义IFileProvider。我遇到一种情况，我想在中间件中加载图像，然后调整其大小或裁剪它。但这是一个Angular项目，因此部署的应用程序的路径有所不同。我编写的中间件从new PhysicalFileProvider(root)中提取了IFileProvider，然后我就可以像过去使用startup.cs一样使用GetFileInfo()。

Answer 4

.NET Core 3.0

变量1：

string path = System.IO.Directory.GetCurrentDirectory();

Var 2：

string path = AppDomain.CurrentDomain.BaseDirectory.Substring(0, AppDomain.CurrentDomain.BaseDirectory.IndexOf("\\bin"));

Answer 5

感谢@NKosi，但是IHostingEnvironment在MVC core 3中已经过时了！！

根据this：

过时的类型（警告）：

Microsoft.Extensions.Hosting.IHostingEnvironment
Microsoft.AspNetCore.Hosting.IHostingEnvironment
Microsoft.Extensions.Hosting.IApplicationLifetime
Microsoft.AspNetCore.Hosting.IApplicationLifetime
Microsoft.Extensions.Hosting.EnvironmentName
Microsoft.AspNetCore.Hosting.EnvironmentName

新类型：

Microsoft.Extensions.Hosting.IHostEnvironment
Microsoft.AspNetCore.Hosting.IWebHostEnvironment : IHostEnvironment
Microsoft.Extensions.Hosting.IHostApplicationLifetime
Microsoft.Extensions.Hosting.Environments

因此，您必须使用IWebHostEnvironment而不是IHostingEnvironment。

public class HomeController : Controller
{
    private readonly IWebHostEnvironment _webHostEnvironment;

    public HomeController(IWebHostEnvironment webHostEnvironment)
    {
        _webHostEnvironment= webHostEnvironment;
    }

    public IActionResult Index()
    {
        string webRootPath = _webHostEnvironment.WebRootPath;
        string contentRootPath = _webHostEnvironment.ContentRootPath;

        return Content(webRootPath + "\n" + contentRootPath);
    }
}

如何在ASP.Net Core中为Server.MapPath获取绝对路径

5 个答案:

.NET Core 3.0