MVC中对VIEW的理解,通过前台BaseController来理解面向对象

首先它是一个具有返回类型为ViewResult的一个方法,也就是说,我们可以通过返回ViewResult对象来代替View()方法,下面的操作是合法的
     ViewData.Model = model;
            return new ViewResult
            {
                ViewName = viewName,
                MasterName = this.MasterFile,
                ViewData = ViewData,
                TempData = TempData
            };
    它在一般情况下等同于return view(model),这是微软为我们封装好的方法,让我们省去了不少代码,它的view(object model)方法原型可能是这样的
        protected internal ViewResult View(object model)
        {
          ViewData.Model = model;
            return new ViewResult
            {
                ViewName = viewName,
                MasterName = this.MasterFile,
                ViewData = ViewData,
                TempData = TempData
            };
        }
        呵呵,我们有时,希望在后台通过调用masterfile的方法来动态改变模版页,可以这样来实现
      public abstract class BaseController : Controller
       {
        /// <summary>
        /// 根据用户角色,返回它的模版页
        /// 子类可以直接访问本属性
        /// </summary>
        protected string MasterFile
        {
            get
            {
                return UIHelper.GetMasterPage(Tsingda.XXB.Common.WebSession.UserRole);
            }
        }
        /// <summary>
        /// 重写controller的View方法,使它可以根据用户角色应用指定视图
        /// </summary>
        protected new ViewResult View(string viewName, object model)
        {
            ViewData.Model = model;
            return new ViewResult
            {
                ViewName = viewName,
                MasterName = this.MasterFile,
                ViewData = ViewData,
                TempData = TempData
            };
        }
 }

   /// <summary>
    /// 前台通用方法
    /// </summary>
    public partial class UIHelper
    {
        /// <summary>
        /// 根据用户角色,得到指定的模板
        /// <param name="role"></param>
        /// <returns></returns>
        public static string GetMasterPage(Tsingda.XXB.Common.CustomEnum.UserRole role)
        {
            string masterPageFile = "";
            switch (role)
            {
                case Common.CustomEnum.UserRole.Student:
                    masterPageFile = "~/Views/Shared/StudentCenter.Master";
                    break;
                case Common.CustomEnum.UserRole.Teacher:
                    masterPageFile = "~/Views/Shared/TeacherCenter.Master";
                    break;
                case Common.CustomEnum.UserRole.Parents:
                    masterPageFile = "~/Views/Shared/ParentCenter.Master";
                    break;
                case Common.CustomEnum.UserRole.Agents:
                    break;
                case Common.CustomEnum.UserRole.Visitor:
                    masterPageFile = "~/Views/Shared/StudentCenter.Master";
                    break;
            }
            return masterPageFile;
        }
}

而在同一个controller中,如果你的View视图不希望去应用任何模板页,可以写这样一个方法,呵呵
      /// <summary>
        /// 返回没有母板页的视图
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        protected ViewResult ViewNotMasterFile(object model)
        {
            ViewData.Model = model;
            return new ViewResult
            {
                MasterName = string.Empty,
                ViewData = ViewData,
                TempData = TempData
            };
        }

呵呵,多么灵活法,(因为ASCX视图不能有母板页的,呵呵)

本文转自博客园张占岭(仓储大叔)的博客,原文链接:MVC中对VIEW的理解,通过前台BaseController来理解面向对象,如需转载请自行联系原博主。

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