在Asp.net MVC 3 web应用程序中，我们会用到与，对比一下： 

 

ViewData	ViewBag
它是Key/Value字典集合	它是类型对像
从Asp.net MVC 1 就有了	ASP.NET MVC3 才有
基于Asp.net 3.5 framework	基于Asp.net 4.0与.net framework
ViewData比ViewBag快	ViewBag比ViewData慢
在ViewPage中查询数据时需要转换合适的类型	在ViewPage中查询数据时不需要类型转换
有一些类型转换代码	可读性更好

 

在Controller中使用ViewData:

public ActionResult UsingViewData(){        ViewData["Title"] = " Using ViewData";    ViewData["ProjectName"] = "My Test Project";    ViewData["ProjectDescription"] = "This is Test Project to demo Viewdata and viewbag details";    ViewData["StartDate"] = new DateTime(2011, 1, 1);    ViewData["TotalPrice"] = 1000;    ViewData["TotalDays"] = 100;    Dictionary
     
       stackholder = new Dictionary
      
       ();    stackholder.Add("Client","Mr.  Client");    stackholder.Add("Manager","Mr. Joy");    stackholder.Add("Team Leader","Mr.Toy");    stackholder.Add("Sr. developer", "Mr.dojoy");    stackholder.Add("developer", "Mr. nodoy");    ViewData["stackholder"] = stackholder;    List
       
         modules = new List
        
         ();    modules.Add("Admin module");    modules.Add("ShoppingCart module");    modules.Add("CMS module");    ViewData["modules"] = modules;    return View();}
        
       
      
     

 

对应UsingViewData View的cshtml:

@ViewData["Title"]
 
     
   
      
    
       
Project Name : @ViewData["ProjectName"]
   
      
   
      
            ProjectDescription :        
       
"@ViewData["ProjectDescription"]".
   
      
   
      
             Stack Holder :      
       
      
       
              @foreach ( var stakerholder in ViewData["stackholder"] as Dictionary
        
          )      {              
         
        @stakerholder.Key   : @stakerholder.Value    
      }     
        
       
   
      
   
      
            Project Details:
       
     
       
               module List  :       
        
               @foreach ( var module in ViewData["modules"] as List
         
           )      {              
          
 @module 
      }     
         
        
             
       
     Project StartDate : @ViewData["StartDate"]  
       
     Project TotalPrice: @ViewData["TotalPrice"] 
       
     Project TotaDays  : @ViewData["TotalDays"]    
      
 
     

 

然后是ViewBag:

public ActionResult UsingViewBag(){    ViewBag.Title = " Using ViewBag";    ViewBag.ProjectName = "My Test Project";    ViewBag.ProjectDescription = "This is Test Project to demo Viewdata and viewbag details";    ViewBag.StartDate = new DateTime(2011, 1, 1);    ViewBag.TotalPrice = 1000;    ViewBag.TotalDays = 100;    Dictionary
     
       stackholder = new Dictionary
      
       ();    stackholder.Add("Client", "Mr.  Client");    stackholder.Add("Manager", "Mr. Joy");    stackholder.Add("Team Leader", "Mr.Toy");    stackholder.Add("Sr. developer", "Mr.dojoy");    stackholder.Add("developer", "Mr. nodoy");    ViewBag.stackholder = stackholder;    List
       
         modules = new List
        
         ();    modules.Add("Admin module");    modules.Add("ShoppingCart module");    modules.Add("CMS module");    ViewBag.modules = modules;    return View();}
        
       
      
     

 

对应View UsingViewBag 的cshtml的ViewBag:

@ViewBag.Title
 
     
   
      
    
       
Project Name : @ViewBag.ProjectName
   
      
   
      
            ProjectDescription :        
       
"@ViewBag.ProjectDescription.
   
      
   
      
             Stack Holder :      
       
      
       
              @foreach ( var stakerholder in ViewBag.stackholder )      {              
        
        @stakerholder.Key   : @stakerholder.Value    
      }     
       
   
      
   
      
            Project Details:
       
     
       
               module List  :       
        
               @foreach ( var module in ViewBag.modules )      {              
         
        @module    
      }     
        
             
       
     Project StartDate : @ViewBag.StartDate.ToString("dd-MMM-yyyy") 
       
     Project TotalPrice: @ViewBag.TotalPrice  ₹  
       
     Project TotaDays  : @ViewBag.TotalDays    
      
 
     

 

后面是在Controller中使用ViewBag:

public ActionResult UsingViewBagInControlAndViewDataInView(){    ViewBag.Title = " Using ViewBag In Control And ViewData In View";    ViewBag.ProjectName = "My Test Project";    ViewBag.ProjectDescription = "This is Test Project to demo Viewdata and viewbag details";    ViewBag.StartDate = new DateTime(2011, 1, 1);    ViewBag.TotalPrice = 1000;    ViewBag.TotalDays = 100;    Dictionary
     
       stackholder = new Dictionary
      
       ();    stackholder.Add("Client", "Mr.  Client");    stackholder.Add("Manager", "Mr. Joy");    stackholder.Add("Team Leader", "Mr.Toy");    stackholder.Add("Sr. developer", "Mr.dojoy");    stackholder.Add("developer", "Mr. nodoy");    ViewBag.stackholder = stackholder;    List
       
         modules = new List
        
         ();    modules.Add("Admin module");    modules.Add("ShoppingCart module");    modules.Add("CMS module");    ViewBag.modules = modules;    return View();}
        
       
      
     

 

在UsingViewBagInControlAndViewDataInView.cshtml中使用ViewData来取值：

@ViewData["Title"]
 
     
   
      
    
       
Project Name : @ViewData["ProjectName"]
   
      
   
      
            ProjectDescription :        
       
"@ViewData["ProjectDescription"]".
   
      
   
      
             Stack Holder :      
       
      
       
              @foreach ( var stakerholder in ViewData["stackholder"] as Dictionary
        
          )      {              
         
        @stakerholder.Key   : @stakerholder.Value    
      }     
        
       
   
      
   
      
            Project Details:
       
     
       
               module List  :       
        
               @foreach ( var module in ViewData["modules"] as List
         
           )      {              
          
 @module 
      }     
         
        
             
       
     Project StartDate : @ViewData["StartDate"]  
       
     Project TotalPrice: @ViewData["TotalPrice"] 
       
     Project TotaDays  : @ViewData["TotalDays"]    
      
 
     

 

反过来是这样的: 

public ActionResult UsingViewDataInControlAndViewBagInView(){    ViewData["Title"] = " Using ViewData In Control And ViewBag In View";    ViewData["ProjectName"] = "My Test Project";    ViewData["ProjectDescription"] = "This is Test Project to demo Viewdata and viewbag details";    ViewData["StartDate"] = new DateTime(2011, 1, 1);    ViewData["TotalPrice"] = 1000;    ViewData["TotalDays"] = 100;    Dictionary
     
       stackholder = new Dictionary
      
       ();    stackholder.Add("Client", "Mr.  Client");    stackholder.Add("Manager", "Mr. Joy");    stackholder.Add("Team Leader", "Mr.Toy");    stackholder.Add("Sr. developer", "Mr.dojoy");    stackholder.Add("developer", "Mr. nodoy");    ViewData["stackholder"] = stackholder;    List
       
         modules = new List
        
         ();    modules.Add("Admin module");    modules.Add("ShoppingCart module");    modules.Add("CMS module");    ViewData["modules"] = modules;    return View();}
        
       
      
     

 

在UsingViewDataInControlAndViewBagInView.cshtml 的View中使用ViewBag来取值:

@ViewBag.Title
 
     
   
      
    
       
Project Name : @ViewBag.ProjectName
   
      
   
      
            ProjectDescription :        
       
"@ViewBag.ProjectDescription.
   
      
   
      
             Stack Holder :      
       
      
       
              @foreach ( var stakerholder in ViewBag.stackholder )      {              
        
        @stakerholder.Key   : @stakerholder.Value    
      }     
       
   
      
   
      
            Project Details:
       
     
       
               module List  :       
        
               @foreach ( var module in ViewBag.modules )      {              
         
        @module    
      }     
        
             
       
     Project StartDate : @ViewBag.StartDate.ToString("dd-MMM-yyyy") 
       
     Project TotalPrice: @ViewBag.TotalPrice  ₹  
       
     Project TotaDays  : @ViewBag.TotalDays    
      
 
     

 

这样对比看上去会比较清楚一些。在源代码中的ViewBag是这样的属性:

public dynamic ViewBag {    get {        if (_dynamicViewData == null) {            _dynamicViewData = new DynamicViewDataDictionary(() => ViewData);        }        return _dynamicViewData;    }}

 

ViewData是：

public ViewDataDictionary ViewData {    get {        if (_viewData == null) {            SetViewData(new ViewDataDictionary());        }        return _viewData;    }    set {        SetViewData(value);    }}