nopcommerce开源框架技术总结如何实现把controller中的Model的数据传入VIEW中，并生产相应的Html代码

首先先来看下VIEW代码：

<div class="Show_h1" 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), });
        }

　　下面我们来看看HomepageBestSellersJson的view代码：

@model HomePageBestsellersModel

@using Nop.Web.Models.Catalog;
@if (Model.Products.Count > 0)
{
    int index = 0;
    foreach (var item in Model.Products)
    {
    <dl>	
        <dt><div class="ranks">@(++index)</div><a href="@Url.RouteUrl("Product", new { productId = item.Id })"><img src="@item.DefaultPictureModel.ImageUrl" alt="@item.DefaultPictureModel.AlternateText" title="@item.DefaultPictureModel.Title"/></a></dt>
        <dd>
            <s>@item.ProductPrice.OldPrice</s><br />
            <i class="price">@item.ProductPrice.Price</i><br />
            <a href="@Url.RouteUrl("Product", new { productId = item.Id })" title="@item.DefaultPictureModel.Title">@item.Name</a>
        </dd>
    </dl>
    }
}

　　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！