nopcommerce开源框架技术总结【转】

<div  id="divHomepageBestSellers">
</div> 
$(document).ready(function () {            // 通过ajax来实现 以上html代码的显示
     $.ajax({  cache: false, 
                     type: "POST",
                     url: "@(Url.RouteUrl("HomepageBestSellersJson"))",//这个路由已定义  
               data: { "productThumbPictureSize": 75 }, 
                     success: function (data) { 
                           $("#divHomepageBestSellers").html(data.html); 
                         }, 
                         error:function (xhr, ajaxOptions, thrownError){ } 
                }); 
});

通过ajax来实现调用HomepageBestSellersJson的action，下面我们来看看它的代码

[HttpPost]        
public ActionResult HomepageBestSellersJson(int? productThumbPictureSize,  int? orderBy, int? categoryId)        
{            
        if (!_catalogSettings.ShowBestsellersOnHomepage||_ catalogSettings.NumberOfBestsellersOnHomepage== 0)                
            return Json(new { html = "" });//这一步只是显示的判断，不比理会            
        var model = GetHomePageBestsellersModel(productThumbPictureSize,    orderBy,categoryId);//这是获取model，            
            return Json(new { html = this.RenderPartialViewToString("HomepageBestSellers", model), });        
}

 接下来是我讲的重点了，是如何实现这个的   return Json(new { html = this.RenderPartialViewToString("HomepageBestSellers", model), })；

先来看看RenderPartialViewToString这个方法，从下面代码可以看到他是Controller的拓展方法:

public static class ContollerExtensions    
{         
     public static string RenderPartialViewToString(this Controller controller, string viewName, object model)        
     { //Original source code: http://craftycodeblog.com/2010/05/15/asp-net-mvc-render-partial-view-to-string/            
         if (string.IsNullOrEmpty(viewName))               
             viewName = controller.ControllerContext.RouteData.GetRequiredString("action");           
             controller.ViewData.Model = model;//传入MODEL数据            
             using (var sw = new StringWriter())           
             {                
                   ViewEngineResult viewResult = System.Web.Mvc.ViewEngines.
                                                 Engines.FindPartialView(controller.ControllerContext, viewName);//这一步是找到VIEW 
                   var viewContext = new ViewContext(controller.ControllerContext, viewResult.View, 
                                                     controller.ViewData, controller.TempData, sw);//这步是实现把controller中的Model的数据传入VIEW中，
                                                                         //并通过viewResult.View.Render生成string代码，这样就完成开始的ajax的调用和实现               
                  viewResult.View.Render(viewContext, sw); 
                  return sw.GetStringBuilder().ToString(); 
              } 
    } 
}

 先来看看System.Web.Mvc.ViewEngines.Engines.FindPartialView具体实现和该方法所属类（ThemeableVirtualPathProviderViewEngine ）的继承关系，

public abstract class ThemeableVirtualPathProviderViewEngine : VirtualPathProviderViewEngine
{
      public override ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache)        
      {            
          var mobileDeviceHelper = EngineContext.Current.Resolve<IMobileDeviceHelper>();            
          bool useMobileDevice = mobileDeviceHelper.IsMobileDevice(controllerContext.HttpContext) 
                                 && mobileDeviceHelper.MobileDevicesSupported()                
                                 && !mobileDeviceHelper.CustomerDontUseMobileVersion();           
          string overrideViewName = useMobileDevice ? string.Format("{0}.{1}", partialViewName, _mobileViewModifier) : partialViewName;                 
          ViewEngineResult result = FindThemeablePartialView(controllerContext, overrideViewName, useCache, useMobileDevice); 
          // If we're looking for a Mobile view and couldn't find it try again without modifying the viewname            
          if (useMobileDevice && (result == null || result.View == null))                
              result = FindThemeablePartialView(controllerContext, partialViewName, useCache, false);           
           return result;        
       }

　　   protected virtual ViewEngineResult FindThemeablePartialView(ControllerContext controllerContext,string partialViewName, 
                                                                   bool useCache, bool mobile)       
      {            
          string[] strArray;            
          if (controllerContext == null)           
          {                
             throw new ArgumentNullException("controllerContext");            
          }            
          if (string.IsNullOrEmpty(partialViewName))            
          {                
              throw new ArgumentException("Partial view name cannot be null or empty.", "partialViewName");            
          }            
          var theme = GetCurrentTheme(mobile);           
          string requiredString = controllerContext.RouteData.GetRequiredString("controller");           
          string str2 = this.GetPath(controllerContext, this.PartialViewLocationFormats,
                                     this.AreaPartialViewLocationFormats, "PartialViewLocationFormats", 
                                     partialViewName, requiredString, theme, "Partial", useCache, 
                                     mobile, out strArray);            
          if (string.IsNullOrEmpty(str2))            
          {                
              return new ViewEngineResult(strArray);           
          }            
          return new ViewEngineResult(this.CreatePartialView(controllerContext, str2), this);        
      }
     
      protected virtual string GetPath(ControllerContext controllerContext, string[] locations, 
                                       string[] areaLocations, string locationsPropertyName, 
                                       string name, string controllerName, string theme, string cacheKeyPrefix, 
                                       bool useCache, bool mobile, out string[] searchedLocations)        
      {            
          searchedLocations = _emptyLocations;            
          if (string.IsNullOrEmpty(name))            
          {                
              return string.Empty;            
          }            
           string areaName = GetAreaName(controllerContext.RouteData);//little hack to get nop's admin area to be in /Administration/ 
                                                                      //instead of /Nop/Admin/ or Areas/Admin/            
           if (!string.IsNullOrEmpty(areaName) && areaName.Equals("admin", StringComparison.InvariantCultureIgnoreCase))           
           {                //admin area does not support mobile devices                
               if (mobile)                
               {                   
                   searchedLocations = new string[0];                    
                   return string.Empty;                
               }                
               var newLocations = areaLocations.ToList();                
               newLocations.Insert(0, "~/Administration/Views/{1}/{0}.cshtml");              
               newLocations.Insert(0, "~/Administration/Views/{1}/{0}.vbhtml");                
               newLocations.Insert(0, "~/Administration/Views/Shared/{0}.cshtml");                
               newLocations.Insert(0, "~/Administration/Views/Shared/{0}.vbhtml");                
               areaLocations = newLocations.ToArray();            
            }            
            bool flag = !string.IsNullOrEmpty(areaName);            
            List<ViewLocation> viewLocations = GetViewLocations(locations, flag ? areaLocations : null);            
            if (viewLocations.Count == 0)           
            {                
                throw new InvalidOperationException(
                           string.Format(CultureInfo.CurrentCulture, 
                          "Properties cannot be null or empty.", 
                           new object[] { locationsPropertyName }));            
            }            
             bool flag2 = IsSpecificPath(name);            
             string key = this.CreateCacheKey(cacheKeyPrefix, name, flag2 ? string.Empty : controllerName, areaName, theme);            
             if (useCache)           
             {                
                 var cached = this.ViewLocationCache.GetViewLocation(controllerContext.HttpContext, key);                
                 if (cached != null)               
                 {                   
                    return cached;                
                 }            
              }            
              if (!flag2)            
              {               
                  return this.GetPathFromGeneralName(controllerContext, viewLocations, name,
                                                     controllerName, areaName, theme, key, ref searchedLocations);           
              }            
                  return this.GetPathFromSpecificName(controllerContext, name, key, ref searchedLocations);        
      }

}

 还有一些具体的方法没有给出，希望大家去看看nop的源码会有很大的收获的，也许我讲的不怎么清洗，但是我希望大家能够理解大致的流程，这功能对我们来说是很有用的，阿门！