[英]In ASP.NET MVC 5 Server.MapPath() returning path with double backslashes
[英]How to get absolute path in ASP.Net Core alternative way for Server.MapPath
如何在ASP net core中獲取Server.MapPath
絕對路徑替代方式
我曾嘗試使用IHostingEnvironment
但它沒有給出正確的結果。
IHostingEnvironment env = new HostingEnvironment();
var str1 = env.ContentRootPath; // Null
var str2 = env.WebRootPath; // Null, both doesn't give any result
我在wwwroot文件夾中有一個圖像文件 (Sample.PNG) 我需要獲取此絕對路徑。
從 .Net Core v3.0 開始,訪問WebRootPath
應該是IWebHostEnvironment
,該WebRootPath
已移至 Web 特定環境界面。
將IWebHostEnvironment
作為依賴項注入依賴類。 該框架將為您填充它
public class HomeController : Controller {
private IWebHostEnvironment _hostEnvironment;
public HomeController(IWebHostEnvironment environment) {
_hostEnvironment = environment;
}
[HttpGet]
public IActionResult Get() {
string path = Path.Combine(_hostEnvironment.WebRootPath, "Sample.PNG");
return View();
}
}
您可以更進一步,創建自己的路徑提供程序服務抽象和實現。
public interface IPathProvider {
string MapPath(string path);
}
public class PathProvider : IPathProvider {
private IWebHostEnvironment _hostEnvironment;
public PathProvider(IWebHostEnvironment environment) {
_hostEnvironment = environment;
}
public string MapPath(string path) {
string filePath = Path.Combine(_hostEnvironment.WebRootPath, path);
return filePath;
}
}
並將IPathProvider
注入依賴類。
public class HomeController : Controller {
private IPathProvider pathProvider;
public HomeController(IPathProvider pathProvider) {
this.pathProvider = pathProvider;
}
[HttpGet]
public IActionResult Get() {
string path = pathProvider.MapPath("Sample.PNG");
return View();
}
}
確保將服務注冊到 DI 容器
services.AddSingleton<IPathProvider, PathProvider>();
* Hack *不推薦,但僅供參考,您可以使用var abs = Path.GetFullPath("~/Content/Images/Sample.PNG").Replace("~\\\\","");
從相對路徑獲取絕對路徑var abs = Path.GetFullPath("~/Content/Images/Sample.PNG").Replace("~\\\\","");
更喜歡上面的 DI/Service 方法,但如果您處於非 DI 情況(例如,使用Activator
實例化的類),這將起作用。
變量 1:
string path = System.IO.Directory.GetCurrentDirectory();
變量 2:
string path = AppDomain.CurrentDomain.BaseDirectory.Substring(0, AppDomain.CurrentDomain.BaseDirectory.IndexOf("\\bin"));
例如我想定位~/wwwroot/CSS
public class YourController : Controller
{
private readonly IWebHostEnvironment _webHostEnvironment;
public YourController (IWebHostEnvironment webHostEnvironment)
{
_webHostEnvironment= webHostEnvironment;
}
public IActionResult Index()
{
string webRootPath = _webHostEnvironment.WebRootPath;
string contentRootPath = _webHostEnvironment.ContentRootPath;
string path ="";
path = Path.Combine(webRootPath , "CSS");
//or path = Path.Combine(contentRootPath , "wwwroot" ,"CSS" );
return View();
}
}
此外,如果您沒有控制器或服務,請按照最后一部分並將其注冊為單例。 然后,在 Startup.ConfigureServices 中:
services.AddSingleton<your_class_Name>();
最后,在需要的地方注入your_class_Name
。
例如我想定位~/wwwroot/CSS
public class YourController : Controller
{
private readonly IHostingEnvironment _HostEnvironment;
public YourController (IHostingEnvironment HostEnvironment)
{
_HostEnvironment= HostEnvironment;
}
public ActionResult Index()
{
string webRootPath = _HostEnvironment.WebRootPath;
string contentRootPath = _HostEnvironment.ContentRootPath;
string path ="";
path = Path.Combine(webRootPath , "CSS");
//or path = Path.Combine(contentRootPath , "wwwroot" ,"CSS" );
return View();
}
}
感謝@NKosi,但IHostingEnvironment
在 MVC 核心 3 中已過時!!
根據這個:
過時的類型(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
新類型:
Microsoft.Extensions.Hosting.IHostEnvironment
Microsoft.AspNetCore.Hosting.IWebHostEnvironment : IHostEnvironment
Microsoft.Extensions.Hosting.IHostApplicationLifetime
Microsoft.Extensions.Hosting.Environments
所以你必須使用IWebHostEnvironment
而不是IHostingEnvironment
。
更好的解決方案是使用IFileProvider.GetFileInfo()
方法。
public IActionResult ResizeCat([FromServices] IFileProvider fileProvider)
{
// get absolute path (equivalent to MapPath)
string absolutePath = fileProvider.GetFileInfo("/assets/images/cat.jpg").PhysicalPath;
...
}
您必須像這樣注冊IFileProvider
才能通過 DI 訪問它:
// 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);
}
正如你所看到的,這個邏輯(文件來自哪里)可能會變得非常復雜,但如果它發生變化,你的代碼不會中斷。
如果您有一些特殊的邏輯,您可以使用new PhysicalFileProvider(root)
創建自定義IFileProvider
。 我有一種情況,我想在中間件中加載圖像,然后調整大小或裁剪它。 但它是一個 Angular 項目,因此部署的應用程序的路徑不同。 我編寫的中間件從startup.cs
獲取IFileProvider
,然后我可以像過去使用MapPath
一樣使用GetFileInfo()
。
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