我想根據當前的UI文化在運行時更改視圖位置。我怎樣才能實現這與默認的Web窗體視圖引擎？如何更改ASP.NET MVC中的默認視圖位置方案？
基本上我想知道如何實現WebFormViewEngine什麼是custom IDescriptorFilter在Spark。
是否有其他的視圖引擎，它給了我視圖位置的運行時控制？
編輯：我的網址應該看起來如下{lang}/{controller}/{action}/{id}。我不需要依賴於語言的控制器，並且視圖是用資源本地化的。然而，少數觀點在某些語言中會有所不同。所以我需要告訴視圖引擎首先查找語言特定的文件夾。
一個簡單的解決辦法是，從ViewEngines.Engines收集相應的ViewEngine你Appication_Start弄個並更新其ViewLocationFormats陣列和PartialViewLocationFormats。沒有hackery：它是默認讀/寫的。
protected void Application_Start()
{
...
// Allow looking up views in ~/Features/ directory
var razorEngine = ViewEngines.Engines.OfType<RazorViewEngine>().First();
razorEngine.ViewLocationFormats = razorEngine.ViewLocationFormats.Concat(new string[]
{
"~/Features/{1}/{0}.cshtml"
}).ToArray();
...
// also: razorEngine.PartialViewLocationFormats if required
}
默認一個剃鬚刀looks like this：
ViewLocationFormats = new string[]
{
"~/Views/{1}/{0}.cshtml",
"~/Views/{1}/{0}.vbhtml",
"~/Views/Shared/{0}.cshtml",
"~/Views/Shared/{0}.vbhtml"
};
注意，您可能需要更新PartialViewLocationFormats也。
我相信解決的辦法是創建自己的ViewEngine，它繼承自WebFormViewEngine。在構造函數中，它應該檢查當前線程的當前UI文化並添加適當的位置。只是不要忘記將它添加到你的視圖引擎。
這應該是這個樣子：
public class ViewEngine : WebFormViewEngine
{
public ViewEngine()
{
if (CultureIsX())
ViewLocationFormats = new string[]{"route1/controller.aspx"};
if (CultureIsY())
ViewLocationFormats = new string[]{"route2/controller.aspx"};
}
}
在Global.asax中：
ViewEngines.Engines.Add(new ViewEngine());
VirtualPathProviderViewEngine.GetPathFromGeneralName必須改變，以允許從航線的附加參數。它不公開，這就是爲什麼你必須複製GetPath,GetPathFromGeneralName,IsSpecificPath ...到你自己的ViewEngine實施。
你是對的：這看起來像一個完整的重寫。我希望GetPathFromGeneralName是公開的。
using System.Web.Mvc;
using System;
using System.Web.Hosting;
using System.Globalization;
using System.Linq;
namespace MvcLocalization
{
public class LocalizationWebFormViewEngine : WebFormViewEngine
{
private const string _cacheKeyFormat = ":ViewCacheEntry:{0}:{1}:{2}:{3}:";
private const string _cacheKeyPrefix_Master = "Master";
private const string _cacheKeyPrefix_Partial = "Partial";
private const string _cacheKeyPrefix_View = "View";
private static readonly string[] _emptyLocations = new string[0];
public LocalizationWebFormViewEngine()
{
base.ViewLocationFormats = new string[] {
"~/Views/{1}/{2}/{0}.aspx",
"~/Views/{1}/{2}/{0}.ascx",
"~/Views/Shared/{2}/{0}.aspx",
"~/Views/Shared/{2}/{0}.ascx" ,
"~/Views/{1}/{0}.aspx",
"~/Views/{1}/{0}.ascx",
"~/Views/Shared/{0}.aspx",
"~/Views/Shared/{0}.ascx"
};
}
private VirtualPathProvider _vpp;
public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
if (controllerContext == null)
throw new ArgumentNullException("controllerContext");
if (String.IsNullOrEmpty(viewName))
throw new ArgumentException("viewName");
string[] viewLocationsSearched;
string[] masterLocationsSearched;
string controllerName = controllerContext.RouteData.GetRequiredString("controller");
string viewPath = GetPath(controllerContext, ViewLocationFormats, "ViewLocationFormats", viewName, controllerName, _cacheKeyPrefix_View, useCache, out viewLocationsSearched);
string masterPath = GetPath(controllerContext, MasterLocationFormats, "MasterLocationFormats", masterName, controllerName, _cacheKeyPrefix_Master, useCache, out masterLocationsSearched);
if (String.IsNullOrEmpty(viewPath) || (String.IsNullOrEmpty(masterPath) && !String.IsNullOrEmpty(masterName)))
{
return new ViewEngineResult(viewLocationsSearched.Union(masterLocationsSearched));
}
return new ViewEngineResult(CreateView(controllerContext, viewPath, masterPath), this);
}
private string GetPath(ControllerContext controllerContext, string[] locations, string locationsPropertyName, string name, string controllerName, string cacheKeyPrefix, bool useCache, out string[] searchedLocations)
{
searchedLocations = _emptyLocations;
if (String.IsNullOrEmpty(name))
return String.Empty;
if (locations == null || locations.Length == 0)
throw new InvalidOperationException();
bool nameRepresentsPath = IsSpecificPath(name);
string cacheKey = CreateCacheKey(cacheKeyPrefix, name, (nameRepresentsPath) ? String.Empty : controllerName);
if (useCache)
{
string result = ViewLocationCache.GetViewLocation(controllerContext.HttpContext, cacheKey);
if (result != null)
{
return result;
}
}
return (nameRepresentsPath) ?
GetPathFromSpecificName(controllerContext, name, cacheKey, ref searchedLocations) :
GetPathFromGeneralName(controllerContext, locations, name, controllerName, cacheKey, ref searchedLocations);
}
private string GetPathFromGeneralName(ControllerContext controllerContext, string[] locations, string name, string controllerName, string cacheKey, ref string[] searchedLocations)
{
string result = String.Empty;
searchedLocations = new string[locations.Length];
string language = controllerContext.RouteData.Values["lang"].ToString();
for (int i = 0; i < locations.Length; i++)
{
string virtualPath = String.Format(CultureInfo.InvariantCulture, locations[i], name, controllerName,language);
if (FileExists(controllerContext, virtualPath))
{
searchedLocations = _emptyLocations;
result = virtualPath;
ViewLocationCache.InsertViewLocation(controllerContext.HttpContext, cacheKey, result);
break;
}
searchedLocations[i] = virtualPath;
}
return result;
}
private string CreateCacheKey(string prefix, string name, string controllerName)
{
return String.Format(CultureInfo.InvariantCulture, _cacheKeyFormat,
GetType().AssemblyQualifiedName, prefix, name, controllerName);
}
private string GetPathFromSpecificName(ControllerContext controllerContext, string name, string cacheKey, ref string[] searchedLocations)
{
string result = name;
if (!FileExists(controllerContext, name))
{
result = String.Empty;
searchedLocations = new[] { name };
}
ViewLocationCache.InsertViewLocation(controllerContext.HttpContext, cacheKey, result);
return result;
}
private static bool IsSpecificPath(string name)
{
char c = name[0];
return (c == '~' || c == '/');
}
}
}
1）從剃刀視圖引擎擴展類
public class LocalizationWebFormViewEngine : RazorViewEngine
2）添加的部分的位置的格式
public LocalizationWebFormViewEngine()
{
base.PartialViewLocationFormats = new string[] {
"~/Views/{2}/{1}/{0}.cshtml",
"~/Views/{2}/{1}/{0}.aspx",
"~/Views/{2}/Shared/{0}.cshtml",
"~/Views/{2}/Shared/{0}.aspx"
};
base.ViewLocationFormats = new string[] {
"~/Views/{2}/{1}/{0}.cshtml",
"~/Views/{2}/{1}/{0}.aspx",
"~/Views/{2}/Shared/{0}.cshtml",
"~/Views/{2}/Shared/{0}.aspx"
};
}
3）創建爲局部視圖的覆蓋方法渲染
public override ViewEngineResult FindPartialView(ControllerContext controllerContext, String partialViewName, Boolean useCache)
{
if (controllerContext == null)
{
throw new ArgumentNullException("controllerContext");
}
if (String.IsNullOrEmpty(partialViewName))
{
throw new ArgumentException("partialViewName");
}
string[] partialViewLocationsSearched;
string controllerName = controllerContext.RouteData.GetRequiredString("controller");
string partialPath = GetPath(controllerContext, PartialViewLocationFormats, "PartialViewLocationFormats", partialViewName, controllerName, _cacheKeyPrefix_Partial, useCache, out partialViewLocationsSearched);
return new ViewEngineResult(CreatePartialView(controllerContext, partialPath), this);}
}
下面是一個沒有重寫的本地化視圖引擎。
簡而言之，引擎會每次將新位置插入視圖位置查看視圖。引擎將使用兩種字符語言來查找視圖。所以如果當前的語言是es（西班牙語），它會查找~/Views/Home/Index.es.cshtml。
查看代碼評論瞭解更多詳情。
更好的方法是重寫視圖位置被解析的方式，但方法不可覆蓋;也許在ASP.NET MVC 5？
public class LocalizedViewEngine : RazorViewEngine
{
private string[] _defaultViewLocationFormats;
public LocalizedViewEngine()
: base()
{
// Store the default locations which will be used to append
// the localized view locations based on the thread Culture
_defaultViewLocationFormats = base.ViewLocationFormats;
}
public override ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache)
{
AppendLocalizedLocations();
return base.FindPartialView(controllerContext, partialViewName, useCache:fase);
}
public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
AppendLocalizedLocations();
returnbase.FindView(controllerContext, viewName, masterName, useCache:false);
}
private void AppendLocalizedLocations()
{
// Use language two letter name to identify the localized view
string lang = Thread.CurrentThread.CurrentUICulture.TwoLetterISOLanguageName;
// Localized views will be in the format "{action}.{lang}.cshtml"
string localizedExtension = string.Format(".{0}.cshtml", lang);
// Create an entry for views and layouts using localized extension
string view = "~/Views/{1}/{0}.cshtml".Replace(".cshtml", localizedExtension);
string shared = "~/Views/{1}/Shared/{0}".Replace(".cshtml", localizedExtension);
// Create a copy of the default view locations to modify
var list = _defaultViewLocationFormats.ToList();
// Insert the new locations at the top of the list of locations
// so they're used before non-localized views.
list.Insert(0, shared);
list.Insert(0, view);
base.ViewLocationFormats = list.ToArray();
}
}
您也可以在http://www.codeplex.com/oxite項目中看到實現。 – pocheptsov 2009-05-26 09:53:21
對不起，這是不好的解決方案，因爲ViewEngine的實例在線程中共享，我需要根據線程UI文化渲染不同的視圖。 – 2009-05-26 10:19:34
也許有可能爲每種文化添加viewEngine並重寫findView方法來中斷它們（如果線程不同）？只是一個奇怪的想法... – 2009-05-26 10:40:35