[转]Asp.net MVC中的ViewData与ViewBag-白红宇

[转]Asp.net MVC中的ViewData与ViewBag

阅读量：4710 次

发布时间：2019-06-10

本文共 7405 字，大约阅读时间需要 24 分钟。

本文转自：

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); } }

具体细节在这儿不深入了，这里只是抛砖引玉。希望对您Asp.net MVC开发有帮助。

作者：出处：本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。该文章也同时发布在我的独立博客中-。

转载于:https://www.cnblogs.com/freeliver54/p/6490899.html

你可能感兴趣的文章