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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。
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