【ASP.NET MVC系列】浅谈ASP.NET MVC八大类扩展(…

2018-06-22 07:57:46来源：未知阅读 ()

lASP.NET MVC系列文章

【01】浅谈Google Chrome浏览器（理论篇）

【02】浅谈Google Chrome浏览器（操作篇）（上）

【03】浅谈Google Chrome浏览器（操作篇）（下）

【04】浅谈ASP.NET框架

【05】浅谈ASP.NET MVC运行过程

【06】浅谈ASP.NET MVC 控制器

【07】浅谈ASP.NET MVC 路由

【08】浅谈ASP.NET MVC 视图

【09】浅谈ASP.NET MVC 视图与控制器传递数据

【10】浅谈jqGrid 在ASP.NET MVC中增删改查

【11】浅谈ASP.NET 页面之间传值的几种方式

【12】浅谈缓存技术在ASP.NET中的运用

【13】浅谈NuGet在VS中的运用

【14】浅谈ASP.NET 程序发布过程

【15】浅谈数据注解和验证

【16】浅谈依赖注入

【17】浅谈表单和HTML辅助方法

【18】浅谈基于APS.NET身份验证

【19】浅谈ASP.NET MVC 模型

【20】浅谈ASP.NET MVC 单元测试

【21】浅谈ASP.NET MVC网络安全;

【22】浅谈ASP.NET MVC八大类扩展

【23】再谈ASP.NET MVC Routing

【24】浅谈ASP.NET 高级话题

【25】浅谈大型ASP.NET MVC项目（含DEMO）

【26】下一系列：ASP.NET WebAPI

一引入背景

我们知道，MVC基架为我们提供了很多基础类，当需要使用时，只需调用即可，以ActionResult为例，其有很多子类，如ContentResult,EmptyResult,FileResult,HttpStatusCodeResult,JavaScriptResult,JsonResult,RedirectResult,RedirectToRouteResult,ViewResultBase,FileContentResult,FilePathResult,FileStreamResult,ViewResult,PartialResult,

然而，尽管MVC基架提供了众多类供我们调用，但却并不是包括所有功能的类，比如，我需要返回XML格式的数据，或下载CSV格式的数据，此时，MVC基架就没提供相应的类。因此，MVC类的扩展就迫在眉睫了。

在本篇文章中，主要讲解MVC比较核心的八大扩展类，一共分为两篇，即浅谈ASP.NET MVC八大类扩展(上篇)和浅谈ASP.NET MVC八大类扩展(下篇)。

其中，本篇文章主要讲解MVC基架提供的ActionResult及其子孙类，自定义扩展XMLResult和CsvResult，下篇文章将讲解剩下的七大类自定义扩展：Filter扩展，RazorViewEngine扩展，HtmlHelper扩展，Validator扩展，ModelBinder扩展，ControllerFactory注入扩展，Lambda 树扩展。

二 ASP.NET MVC扩展概述

但凡涉及到架构，我们首先都会关心安全性，稳定性，可扩展性等特征，当然，ASO.NET MVC也不例外，MVC之所以比WebForm流行，不仅仅在于其实现前后端的松耦合，而且其也支持强大的自定义扩展，在本篇文章中，我们就是运用MVC支持自定义扩展这一特性来进行自定义扩展，从而实现个性化项目需求。

三代码实例

（一） ActionResult扩展

1 AtionResult内置扩展

ASP.NET MVC提供了如下内置扩展类.

1.1 上图简要概述

(1)ActionResult类继承Object类；

(2)ContentResult,EmptyResult,FileResult,HttpStatusCodeResult,JavaScriptResult,JsonResult,ViewResultBase,RedirectToRouteResult,RedirectResult 九大类继承类ActionResult；

(3)FileContentResult，FilePathResult，FileStreamResult 三大类继承类FileResult；

(4)ViewResult,PartialViewResult两大类继承类ViewResultBase;

1.2 ActionResult讲解

功能：封装一个操作方法的结果并用于代表该操作方法执行框架级操作。

在Mvc中，我们对如下代码再熟悉不过了。

public ActionResult Index()
 {
    return View();
 }

F12查看ActionResult定义

 1 namespace System.Web.Mvc
 2 {
 3     //
 4     // 摘要:
 5     //     表示操作方法的结果。
 6     public abstract class ActionResult
 7     {
 8         //
 9         // 摘要:
10         //     初始化 System.Web.Mvc.ActionResult 类的新实例。
11         protected ActionResult();
12 
13         //
14         // 摘要:
15         //     通过从 System.Web.Mvc.ActionResult 类继承的自定义类型，启用对操作方法结果的处理。
16         //
17         // 参数:
18         //   context:
19         //     用于执行结果的上下文。上下文信息包括控制器、HTTP 内容、请求上下文和路由数据。
20         public abstract void ExecuteResult(ControllerContext context);
21     }
22 }

View Code

不难看出，ActionResult具有如下特征：

(1)抽象类；

(2)一个只可继承的构造函数；

(3)一个未实现的抽象方法；

1.2.1 ContentResult讲解

功能：表示用户定义的内容类型，该类型是操作方法的结果。

定义：查看定义

不难看出，ContentResult具有如下特征：

(1)继承自类ActionResult

(2)包含一个构造方法，一个重写ActionResultl类的抽象方法ExecuteResult(ControllerContext context)，和三个属性；

(3)完整定义

 1 public class ContentResult : ActionResult
 2 {
 3     // Methods
 4     public override void ExecuteResult(ControllerContext context)
 5     {
 6         if (context == null)
 7         {
 8             throw new ArgumentNullException("context");
 9         }
10         HttpResponseBase response = context.HttpContext.Response;
11         if (!string.IsNullOrEmpty(this.ContentType))
12         {
13             response.ContentType = this.ContentType;
14         }
15         if (this.ContentEncoding != null)
16         {
17             response.ContentEncoding = this.ContentEncoding;
18         }
19         if (this.Content != null)
20         {
21             response.Write(this.Content);
22         }
23     }
24 
25     // Properties
26     public string Content { get; set; }
27 
28     public Encoding ContentEncoding { get; set; }
29 
30     public string ContentType { get; set; }
31 }
32 
33

View Code

(4)我们来看看具体例子：

如我们向页面输出“Alan_beijing”，可采取如下两种方式。

方式一：

1 public ContentResult ContextResultTest()
2 {
3    return Content("Alan_beijing");
4 }

测试结果

方式二

1 public ContentResult ContextResultTest()
2         {
3             //string str =  "<html>" + "<head></head>" + "<body>" + "Alan_beijing" + "</body>" + "</html>";
4             string str = "<html><head></head></body>Alan_beijing</body></html>";
5             return Content(str);
6         }

View Code

测试结果

总之，大家在使用时，可以把ContentResult当作Responce.Write()使用。

1.2.2 EmptyResult

功能：表示一个不执行任何操作的结果，如不返回任何内容的控制器操作方法。

(1)查看定义

(2)完整定义

 1 public class EmptyResult : ActionResult
 2 {
 3     // Fields
 4     private static readonly EmptyResult _singleton = new EmptyResult();
 5 
 6     // Methods
 7     public override void ExecuteResult(ControllerContext context)
 8     {
 9     }
10 
11     // Properties
12     internal static EmptyResult Instance =>
13         _singleton;
14 }

View Code

(3)总结

EmptyResult不执行任何操作，相当于如下功能。

1 public ContentResult ContextResultTest()
2 {
3    return Content("");
4 }

1.2.3 FileResult

功能：表示一个用于将二进制文件内容发送到响应的基类。

(1)查看定义

(2)完整定义

  1 public abstract class FileResult : ActionResult
  2 {
  3     // Fields
  4     private string _fileDownloadName;
  5 
  6     // Methods
  7     protected FileResult(string contentType)
  8     {
  9         if (string.IsNullOrEmpty(contentType))
 10         {
 11             throw new ArgumentException(MvcResources.Common_NullOrEmpty, "contentType");
 12         }
 13         this.ContentType = contentType;
 14     }
 15 
 16     public override void ExecuteResult(ControllerContext context)
 17     {
 18         if (context == null)
 19         {
 20             throw new ArgumentNullException("context");
 21         }
 22         HttpResponseBase response = context.HttpContext.Response;
 23         response.ContentType = this.ContentType;
 24         if (!string.IsNullOrEmpty(this.FileDownloadName))
 25         {
 26             string headerValue = ContentDispositionUtil.GetHeaderValue(this.FileDownloadName);
 27             context.HttpContext.Response.AddHeader("Content-Disposition", headerValue);
 28         }
 29         this.WriteFile(response);
 30     }
 31 
 32     protected abstract void WriteFile(HttpResponseBase response);
 33 
 34     // Properties
 35     public string ContentType { get; private set; }
 36 
 37     public string FileDownloadName
 38     {
 39         get => 
 40             (this._fileDownloadName ?? string.Empty);
 41         set
 42         {
 43             this._fileDownloadName = value;
 44         }
 45     }
 46 
 47     // Nested Types
 48     internal static class ContentDispositionUtil
 49     {
 50         // Fields
 51         private const string HexDigits = "0123456789ABCDEF";
 52 
 53         // Methods
 54         private static void AddByteToStringBuilder(byte b, StringBuilder builder)
 55         {
 56             builder.Append('%');
 57             int num = b;
 58             AddHexDigitToStringBuilder(num >> 4, builder);
 59             AddHexDigitToStringBuilder(num % 0x10, builder);
 60         }
 61 
 62         private static void AddHexDigitToStringBuilder(int digit, StringBuilder builder)
 63         {
 64             builder.Append("0123456789ABCDEF"[digit]);
 65         }
 66 
 67         private static string CreateRfc2231HeaderValue(string filename)
 68         {
 69             StringBuilder builder = new StringBuilder("attachment; filename*=UTF-8''");
 70             foreach (byte num in Encoding.UTF8.GetBytes(filename))
 71             {
 72                 if (IsByteValidHeaderValueCharacter(num))
 73                 {
 74                     builder.Append((char) num);
 75                 }
 76                 else
 77                 {
 78                     AddByteToStringBuilder(num, builder);
 79                 }
 80             }
 81             return builder.ToString();
 82         }
 83 
 84         public static string GetHeaderValue(string fileName)
 85         {
 86             foreach (char ch in fileName)
 87             {
 88                 if (ch > '\x007f')
 89                 {
 90                     return CreateRfc2231HeaderValue(fileName);
 91                 }
 92             }
 93             ContentDisposition disposition = new ContentDisposition {
 94                 FileName = fileName
 95             };
 96             return disposition.ToString();
 97         }
 98 
 99         private static bool IsByteValidHeaderValueCharacter(byte b)
100         {
101             if ((0x30 <= b) && (b <= 0x39))
102             {
103                 return true;
104             }
105             if ((0x61 <= b) && (b <= 0x7a))
106             {
107                 return true;
108             }
109             if ((0x41 <= b) && (b <= 90))
110             {
111                 return true;
112             }
113             switch (b)
114             {
115                 case 0x3a:
116                 case 0x5f:
117                 case 0x7e:
118                 case 0x24:
119                 case 0x26:
120                 case 0x21:
121                 case 0x2b:
122                 case 0x2d:
123                 case 0x2e:
124                     return true;
125             }
126             return false;
127         }
128     }
129 }

View Code

1.2.4 HttpStatusCodeResult

功能：提供一种用于返回带特定 HTTP 响应状态代码和说明的操作结果的方法。

(1)定义

(2)完整定义

 1 public class HttpStatusCodeResult : ActionResult
 2 {
 3     // Methods
 4     public HttpStatusCodeResult(int statusCode) : this(statusCode, null)
 5     {
 6     }
 7 
 8     public HttpStatusCodeResult(HttpStatusCode statusCode) : this(statusCode, null)
 9     {
10     }
11 
12     public HttpStatusCodeResult(int statusCode, string statusDescription)
13     {
14         this.StatusCode = statusCode;
15         this.StatusDescription = statusDescription;
16     }
17 
18     public HttpStatusCodeResult(HttpStatusCode statusCode, string statusDescription) : this((int) statusCode, statusDescription)
19     {
20     }
21 
22     public override void ExecuteResult(ControllerContext context)
23     {
24         if (context == null)
25         {
26             throw new ArgumentNullException("context");
27         }
28         context.HttpContext.Response.StatusCode = this.StatusCode;
29         if (this.StatusDescription != null)
30         {
31             context.HttpContext.Response.StatusDescription = this.StatusDescription;
32         }
33     }
34 
35     // Properties
36     public int StatusCode { get; private set; }
37 
38     public string StatusDescription { get; private set; }
39 }

View Code

1.2.5 JavaScriptResult

功能：将 JavaScript 内容发送到响应。

(1)定义

(2)完整定义

 1 public class JavaScriptResult : ActionResult
 2 {
 3     // Methods
 4     public override void ExecuteResult(ControllerContext context)
 5     {
 6         if (context == null)
 7         {
 8             throw new ArgumentNullException("context");
 9         }
10         HttpResponseBase response = context.HttpContext.Response;
11         response.ContentType = "application/x-javascript";
12         if (this.Script != null)
13         {
14             response.Write(this.Script);
15         }
16     }
17 
18     // Properties
19     public string Script { get; set; }
20 }

View Code

1.2.6 JsonResult

功能：表示一个类，该类用于将 JSON 格式的内容发送到响应。

(1)定义

(2)完整定义

 1 public class JsonResult : ActionResult
 2 {
 3     // Methods
 4     public JsonResult()
 5     {
 6         this.JsonRequestBehavior = JsonRequestBehavior.DenyGet;
 7     }
 8 
 9     public override void ExecuteResult(ControllerContext context)
10     {
11         if (context == null)
12         {
13             throw new ArgumentNullException("context");
14         }
15         if ((this.JsonRequestBehavior == JsonRequestBehavior.DenyGet) && string.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
16         {
17             throw new InvalidOperationException(MvcResources.JsonRequest_GetNotAllowed);
18         }
19         HttpResponseBase response = context.HttpContext.Response;
20         if (!string.IsNullOrEmpty(this.ContentType))
21         {
22             response.ContentType = this.ContentType;
23         }
24         else
25         {
26             response.ContentType = "application/json";
27         }
28         if (this.ContentEncoding != null)
29         {
30             response.ContentEncoding = this.ContentEncoding;
31         }
32         if (this.Data != null)
33         {
34             JavaScriptSerializer serializer = new JavaScriptSerializer();
35             if (this.MaxJsonLength.HasValue)
36             {
37                 serializer.MaxJsonLength = this.MaxJsonLength.Value;
38             }
39             if (this.RecursionLimit.HasValue)
40             {
41                 serializer.RecursionLimit = this.RecursionLimit.Value;
42             }
43             response.Write(serializer.Serialize(this.Data));
44         }
45     }
46 
47     // Properties
48     public Encoding ContentEncoding { get; set; }
49 
50     public string ContentType { get; set; }
51 
52     public object Data { get; set; }
53 
54     public JsonRequestBehavior JsonRequestBehavior { get; set; }
55 
56     public int? MaxJsonLength { get; set; }
57 
58     public int? RecursionLimit { get; set; }
59 }

View Code

(3)总结

JsonResult首先将指定的对象序列化为Json字符串，然后将字符串写入到HTTP输出流。

1.2.7 RedirectResult

功能：通过重定向到指定的 URI 来控制对应用程序操作的处理。

(1)定义

(2)完整定义

 1 public class RedirectResult : ActionResult
 2 {
 3     // Methods
 4     public RedirectResult(string url) : this(url, false)
 5     {
 6     }
 7 
 8     public RedirectResult(string url, bool permanent)
 9     {
10         if (string.IsNullOrEmpty(url))
11         {
12             throw new ArgumentException(MvcResources.Common_NullOrEmpty, "url");
13         }
14         this.Permanent = permanent;
15         this.Url = url;
16     }
17 
18     public override void ExecuteResult(ControllerContext context)
19     {
20         if (context == null)
21         {
22             throw new ArgumentNullException("context");
23         }
24         if (context.IsChildAction)
25         {
26             throw new InvalidOperationException(MvcResources.RedirectAction_CannotRedirectInChildAction);
27         }
28         string url = UrlHelper.GenerateContentUrl(this.Url, context.HttpContext);
29         context.Controller.TempData.Keep();
30         if (this.Permanent)
31         {
32             context.HttpContext.Response.RedirectPermanent(url, false);
33         }
34         else
35         {
36             context.HttpContext.Response.Redirect(url, false);
37         }
38     }
39 
40     // Properties
41     public bool Permanent { get; private set; }
42 
43     public string Url { get; private set; }
44 }

View Code

1.2.8 RedirectToRouteResult

功能：表示使用指定的路由值字典来执行重定向的结果。

（1）定义

(2)完整定义

 1 public class RedirectToRouteResult : ActionResult
 2 {
 3     // Fields
 4     private RouteCollection _routes;
 5 
 6     // Methods
 7     public RedirectToRouteResult(RouteValueDictionary routeValues) : this(null, routeValues)
 8     {
 9     }
10 
11     public RedirectToRouteResult(string routeName, RouteValueDictionary routeValues) : this(routeName, routeValues, false)
12     {
13     }
14 
15     public RedirectToRouteResult(string routeName, RouteValueDictionary routeValues, bool permanent)
16     {
17         this.Permanent = permanent;
18         this.RouteName = routeName ?? string.Empty;
19         this.RouteValues = routeValues ?? new RouteValueDictionary();
20     }
21 
22     public override void ExecuteResult(ControllerContext context)
23     {
24         if (context == null)
25         {
26             throw new ArgumentNullException("context");
27         }
28         if (context.IsChildAction)
29         {
30             throw new InvalidOperationException(MvcResources.RedirectAction_CannotRedirectInChildAction);
31         }
32         string str = UrlHelper.GenerateUrl(this.RouteName, null, null, this.RouteValues, this.Routes, context.RequestContext, false);
33         if (string.IsNullOrEmpty(str))
34         {
35             throw new InvalidOperationException(MvcResources.Common_NoRouteMatched);
36         }
37         context.Controller.TempData.Keep();
38         if (this.Permanent)
39         {
40             context.HttpContext.Response.RedirectPermanent(str, false);
41         }
42         else
43         {
44             context.HttpContext.Response.Redirect(str, false);
45         }
46     }
47 
48     // Properties
49     public bool Permanent { get; private set; }
50 
51     public string RouteName { get; private set; }
52 
53     internal RouteCollection Routes
54     {
55         get
56         {
57             if (this._routes == null)
58             {
59                 this._routes = RouteTable.Routes;
60             }
61             return this._routes;
62         }
63         set
64         {
65             this._routes = value;
66         }
67     }
68 
69     public RouteValueDictionary RouteValues { get; private set; }
70 }

View Code

1.2.9 ViewResultBase

功能：表示一个用于为视图提供模型并向响应呈现视图的基类。

(1)定义

(2)完整定义

  1 public abstract class ViewResultBase : ActionResult
  2 {
  3     // Fields
  4     private DynamicViewDataDictionary _dynamicViewData;
  5     private TempDataDictionary _tempData;
  6     private ViewDataDictionary _viewData;
  7     private ViewEngineCollection _viewEngineCollection;
  8     private string _viewName;
  9 
 10     // Methods
 11     protected ViewResultBase()
 12     {
 13     }
 14 
 15     public override void ExecuteResult(ControllerContext context)
 16     {
 17         if (context == null)
 18         {
 19             throw new ArgumentNullException("context");
 20         }
 21         if (string.IsNullOrEmpty(this.ViewName))
 22         {
 23             this.ViewName = context.RouteData.GetRequiredString("action");
 24         }
 25         ViewEngineResult result = null;
 26         if (this.View == null)
 27         {
 28             result = this.FindView(context);
 29             this.View = result.View;
 30         }
 31         TextWriter output = context.HttpContext.Response.Output;
 32         ViewContext viewContext = new ViewContext(context, this.View, this.ViewData, this.TempData, output);
 33         this.View.Render(viewContext, output);
 34         if (result != null)
 35         {
 36             result.ViewEngine.ReleaseView(context, this.View);
 37         }
 38     }
 39 
 40     protected abstract ViewEngineResult FindView(ControllerContext context);
 41 
 42     // Properties
 43     public object Model =>
 44         this.ViewData.Model;
 45 
 46     public TempDataDictionary TempData
 47     {
 48         get
 49         {
 50             if (this._tempData == null)
 51             {
 52                 this._tempData = new TempDataDictionary();
 53             }
 54             return this._tempData;
 55         }
 56         set
 57         {
 58             this._tempData = value;
 59         }
 60     }
 61 
 62     public IView View { get; set; }
 63 
 64     [Dynamic]
 65     public object ViewBag
 66     {
 67         [return: Dynamic]
 68         get
 69         {
 70             Func<ViewDataDictionary> viewDataThunk = null;
 71             if (this._dynamicViewData == null)
 72             {
 73                 if (viewDataThunk == null)
 74                 {
 75                     viewDataThunk = () => this.ViewData;
 76                 }
 77                 this._dynamicViewData = new DynamicViewDataDictionary(viewDataThunk);
 78             }
 79             return this._dynamicViewData;
 80         }
 81     }
 82 
 83     public ViewDataDictionary ViewData
 84     {
 85         get
 86         {
 87             if (this._viewData == null)
 88             {
 89                 this._viewData = new ViewDataDictionary();
 90             }
 91             return this._viewData;
 92         }
 93         set
 94         {
 95             this._viewData = value;
 96         }
 97     }
 98 
 99     public ViewEngineCollection ViewEngineCollection
100     {
101         get => 
102             (this._viewEngineCollection ?? ViewEngines.Engines);
103         set
104         {
105             this._viewEngineCollection = value;
106         }
107     }
108 
109     public string ViewName
110     {
111         get => 
112             (this._viewName ?? string.Empty);
113         set
114         {
115             this._viewName = value;
116         }
117     }
118 }

View Code

1.2.10 FileContentResult

功能：将二进制文件的内容发送到响应

定义：

 1 public class FileContentResult : FileResult
 2 {
 3     // Methods
 4     public FileContentResult(byte[] fileContents, string contentType) : base(contentType)
 5     {
 6         if (fileContents == null)
 7         {
 8             throw new ArgumentNullException("fileContents");
 9         }
10         this.FileContents = fileContents;
11     }
12 
13     protected override void WriteFile(HttpResponseBase response)
14     {
15         response.OutputStream.Write(this.FileContents, 0, this.FileContents.Length);
16     }
17 
18     // Properties
19     public byte[] FileContents { get; private set; }
20 }

View Code

1.2.11 FilePathResult

功能：将文件的内容发送到响应。

定义：

 1 public class FilePathResult : FileResult
 2 {
 3     // Methods
 4     public FilePathResult(string fileName, string contentType) : base(contentType)
 5     {
 6         if (string.IsNullOrEmpty(fileName))
 7         {
 8             throw new ArgumentException(MvcResources.Common_NullOrEmpty, "fileName");
 9         }
10         this.FileName = fileName;
11     }
12 
13     protected override void WriteFile(HttpResponseBase response)
14     {
15         response.TransmitFile(this.FileName);
16     }
17 
18     // Properties
19     public string FileName { get; private set; }
20 }

View Code

1.2.12 FilestreamResult

功能：使用Stream实例将二进制内容发送到响应。

定义：

 1 public class FileStreamResult : FileResult
 2 {
 3     // Fields
 4     private const int BufferSize = 0x1000;
 5 
 6     // Methods
 7     public FileStreamResult(Stream fileStream, string contentType) : base(contentType)
 8     {
 9         if (fileStream == null)
10         {
11             throw new ArgumentNullException("fileStream");
12         }
13         this.FileStream = fileStream;
14     }
15 
16     protected override void WriteFile(HttpResponseBase response)
17     {
18         Stream outputStream = response.OutputStream;
19         using (this.FileStream)
20         {
21             byte[] buffer = new byte[0x1000];
22             while (true)
23             {
24                 int count = this.FileStream.Read(buffer, 0, 0x1000);
25                 if (count == 0)
26                 {
27                     return;
28                 }
29                 outputStream.Write(buffer, 0, count);
30             }
31         }
32     }
33 
34     // Properties
35     public Stream FileStream { get; private set; }
36 }

View Code

1.2.13 ViewResult

功能：表示一个类，该类用于使用由IViewEngine对象返回的IView实例来呈现视图。

(1)定义：

 1 public class ViewResult : ViewResultBase
 2 {
 3     // Fields
 4     private string _masterName;
 5 
 6     // Methods
 7     protected override ViewEngineResult FindView(ControllerContext context)
 8     {
 9         ViewEngineResult result = base.ViewEngineCollection.FindView(context, base.ViewName, this.MasterName);
10         if (result.View != null)
11         {
12             return result;
13         }
14         StringBuilder builder = new StringBuilder();
15         foreach (string str in result.SearchedLocations)
16         {
17             builder.AppendLine();
18             builder.Append(str);
19         }
20         throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, MvcResources.Common_ViewNotFound, new object[] { base.ViewName, builder }));
21     }
22 
23     // Properties
24     public string MasterName
25     {
26         get => 
27             (this._masterName ?? string.Empty);
28         set
29         {
30             this._masterName = value;
31         }
32     }
33 }

View Code

1.2.14 PartialResult

功能：表示一个用于将分部视图发送到响应的基类。

(1)定义：

 1 public class PartialViewResult : ViewResultBase
 2 {
 3     // Methods
 4     protected override ViewEngineResult FindView(ControllerContext context)
 5     {
 6         ViewEngineResult result = base.ViewEngineCollection.FindPartialView(context, base.ViewName);
 7         if (result.View != null)
 8         {
 9             return result;
10         }
11         StringBuilder builder = new StringBuilder();
12         foreach (string str in result.SearchedLocations)
13         {
14             builder.AppendLine();
15             builder.Append(str);
16         }
17         throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, MvcResources.Common_PartialViewNotFound, new object[] { base.ViewName, builder }));
18     }
19 }

View Code

2 ActionResult自定义扩展

关于ActionResult的自定义扩展，满足两个条件

(1)继承ActionResult

(2)重写ExecuteResult()方法

2.1 XMLResult

public class XmlResult : ActionResult
    {
        private object _data;

        public XmlResult(object data)
        {
            _data = data;
        }

        public override void ExecuteResult(ControllerContext context)
        {
            var serializer = new XmlSerializer(_data.GetType());
            var response = context.HttpContext.Response;
            response.ContentType = "text/xml";
            serializer.Serialize(response.Output, _data);
        }
    }

Controller

public XmlResult GetEmpInfo()
        {
            EmpInfo empInfo = new EmpInfo()
            {
                Name = "Alan_beijing",
                Address = "China-ShangHai",
                Age=40
            };
            return new XmlResult(empInfo);
        }

Test Result

2.2 CsvResult

 public class CsvResult : FileResult
    {
        private IEnumerable _data;

        public CsvResult(IEnumerable data, string fileName) : base("text/csv")
        {
            _data = data;
            FileDownloadName = fileName;
        }

        protected override void WriteFile(HttpResponseBase response)
        {
            var builder = new StringBuilder();
            var strWriter = new StringWriter(builder);

            foreach (var item in _data)
            {
                var properties = item.GetType().GetProperties();
                foreach (var prop in properties)
                {
                    strWriter.Write(GetValue(item, prop.Name));
                    strWriter.Write(", ");
                }
                strWriter.WriteLine();
            }

            response.Write(builder);
        }

        public static string GetValue(object item, string propName)
        {
            return item.GetType().GetProperty(propName).GetValue(item, null).ToString() ?? "";
        }
    }

Controller

 public CsvResult DownCsvEmpInfo()
        {
            EmpInfo empInfo = new EmpInfo()
            {
                Name = "Alan_beijing",
                Address = "China-ShangHai",
                Age = 40
            };
            return new CsvResult(new List<EmpInfo>() { empInfo }, "empInfo");
        }

测试结果