正文

ActionResult

IP云
IP云V管理员/4 阅读
09/04
提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

ActionResult

public abstract class ActionResult

{

public abstract void ExecuteResult(ControllerContext context);

}

  1. EmptyResult

无论一个Action返回值是Void还是其他数据类型,都会创建相应的ActionResult.

如果一个Action方法的返回值时Void或者Null,会生成一个EmptyResult对象.

EmptyResult主要起到了适配器的作用,让所有的用法保持一致.

ActionInvoker中,执行Action方法后,根据返回值判断

protected virtual ActionResult CreateActionResult(ControllerContext controllerContext, ActionDescriptor actionDescriptor, object actionReturnValue)
{ if (actionReturnValue == null)//Action的返回值为Void或者Null{ return new EmptyResult(); } ActionResult actionResult = (actionReturnValue as ActionResult) ?? new ContentResult { Content = Convert.ToString(actionReturnValue, CultureInfo.InvariantCulture) };//如果返回值不是ActionResult,就创建ContentResult return actionResult; }

EmptyResult

  1. public class EmptyResult : ActionResult
    { private static readonly EmptyResult _singleton = new EmptyResult(); internal static EmptyResult Instance
    { get { return _singleton; } } public override void ExecuteResult(ControllerContext context)
    { } }

    ContentResult

如果Action的返回值不是ActionResult,就创建ContentResult

ContentResult

public class ContentResult : ActionResult
{ public string Content { get; set; } public Encoding ContentEncoding { get; set; } public string ContentType { get; set; } public override void ExecuteResult(ControllerContext context)
{ if (context == null) { throw new ArgumentNullException("context"); } HttpResponseBase response = context.HttpContext.Response; if (!String.IsNullOrEmpty(ContentType)) { response.ContentType = ContentType; } if (ContentEncoding != null) { response.ContentEncoding = ContentEncoding; } if (Content != null) { response.Write(Content); } } }

Controller中定义了几个创建ContentResult的封装方法

  1. protected internal ContentResult Content(string content)
    { return Content(content, null /* contentType */); } protected internal ContentResult Content(string content, string contentType)
    { return Content(content, contentType, null /* contentEncoding */); } protected internal virtual ContentResult Content(string content, string contentType, Encoding contentEncoding)
    { return new ContentResult { Content = content, ContentType = contentType, ContentEncoding = contentEncoding }; }

    FileResult

可以将某个物理文件的内容给客户端.如果指定了文件名,就采用附件的方式下载文件.

FileResult

public abstract class FileResult : ActionResult
{ private string _fileDownloadName; protected FileResult(string contentType)
{ if (String.IsNullOrEmpty(contentType)) { throw new ArgumentException(MvcResources.Common_NullOrEmpty, "contentType"); } ContentType = contentType; } public string ContentType { get; private set; } public string FileDownloadName
{ get { return _fileDownloadName ?? String.Empty; } set { _fileDownloadName = value; } } public override void ExecuteResult(ControllerContext context)
{ if (context == null) { throw new ArgumentNullException("context"); } HttpResponseBase response = context.HttpContext.Response; response.ContentType = ContentType; if (!String.IsNullOrEmpty(FileDownloadName)) { string headerValue = ContentDispositionUtil.GetHeaderValue(FileDownloadName); context.HttpContext.Response.AddHeader("Content-Disposition", headerValue); } WriteFile(response); }
}

文件下载方式有两种

针对文件的响应具有两种形式，即内联(Inline) 和附件(Attachment) 。一般来说，前者会利用浏览器直接打开响应的文件，而后者会以独立的文件下载到客户端。对于后者，我们一般会为下载的文件指定一个文件名，这个文件名可以通过FileResult 的FileDownloadName 属性来指定。文件响应在默认情况下采用内联的方式，如果需要采用附件的形式，需要为响应创建一个名称为"Content-Disposition" 的报头，该报头值的格式为

"attachment; filename={FileDownloadName} "。

有三种FileResult

  • FileContentResult

针对文件内容创建的FileResult.直接将文件内容写入到Response的OutputStream中

FileContentResult

public class FileContentResult : FileResult
{ public FileContentResult(byte[] fileContents, string contentType) : base(contentType)
{ if (fileContents == null) { throw new ArgumentNullException("fileContents"); } FileContents = fileContents; } public byte[] FileContents { get; private set; } protected override void WriteFile(HttpResponseBase response)
{ response.OutputStream.Write(FileContents, 0, FileContents.Length); }}

  • FilePathResult

根据物理文件路径创建FileResult.调用 response.TransmitFile(FileName)输出文件

FilePathResult

public class FilePathResult : FileResult
{ public FilePathResult(string fileName, string contentType) : base(contentType)
{ if (String.IsNullOrEmpty(fileName)) { throw new ArgumentException(MvcResources.Common_NullOrEmpty, "fileName"); } FileName = fileName; } public string FileName { get; private set; } protected override void WriteFile(HttpResponseBase response)
{ response.TransmitFile(FileName); }}

  • FileStreamResult

FileStreamResult

public class FileStreamResult : FileResult
{ private const int BufferSize = 0x1000; public FileStreamResult(Stream fileStream, string contentType) : base(contentType)
{ if (fileStream == null) { throw new ArgumentNullException("fileStream"); } FileStream = fileStream; } public Stream FileStream { get; private set; } protected override void WriteFile(HttpResponseBase response)
{ Stream outputStream = response.OutputStream; using (FileStream) { byte[] buffer = new byte[BufferSize]; while (true) { int bytesRead = FileStream.Read(buffer, 0, BufferSize); if (bytesRead == 0) { // no more data break; } outputStream.Write(buffer, 0, bytesRead); } } }}

  • Controller中定义的封装方法

  1. JavaScriptResult

貌似和浏览器有关系,谷歌不执行,直接返回字符串了

在服务端生成一段JS,作为响应返回给客户端,并且在客户端执行.

JavaScriptResult就是将ContentType设置为javascript,然后直接写入JS内容,因此,完全可以用ContentResult实现这个效果,只需要设置ContentType的类型为Scrippt就可以了

JavaScriptResult

public class JavaScriptResult : ActionResult
{ public string Script { get; set; } public override void ExecuteResult(ControllerContext context)
{ if (context == null) { throw new ArgumentNullException("context"); } HttpResponseBase response = context.HttpContext.Response; response.ContentType = "application/x-javascript"; if (Script != null) { response.Write(Script); } }}

  1. JsonResult

默认情况下,不允许Get请求Json数据

JsonResult

public class JsonResult : ActionResult
{ public JsonResult()
{ JsonRequestBehavior = JsonRequestBehavior.DenyGet; } public Encoding ContentEncoding { get; set; } public string ContentType { get; set; } public object Data { get; set; } public JsonRequestBehavior JsonRequestBehavior { get; set; } public int? MaxJsonLength { get; set; } public int? RecursionLimit { get; set; } public override void ExecuteResult(ControllerContext context)
{ if (context == null) { throw new ArgumentNullException("context"); } if (JsonRequestBehavior == JsonRequestBehavior.DenyGet && String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase)) { throw new InvalidOperationException(MvcResources.JsonRequest_GetNotAllowed); } HttpResponseBase response = context.HttpContext.Response; if (!String.IsNullOrEmpty(ContentType)) { response.ContentType = ContentType; } else { response.ContentType = "application/json"; } if (ContentEncoding != null) { response.ContentEncoding = ContentEncoding; } if (Data != null) { JavaScriptSerializer serializer = new JavaScriptSerializer(); if (MaxJsonLength.HasValue) { serializer.MaxJsonLength = MaxJsonLength.Value; } if (RecursionLimit.HasValue) { serializer.RecursionLimit = RecursionLimit.Value; } response.Write(serializer.Serialize(Data)); } }}

JsonRequestBehavior

public enum JsonRequestBehavior

{

AllowGet,

DenyGet,

}

  1. HttpStatusCodeResult

设置Response的StatusCode

HttpStatusCodeResult

public HttpStatusCodeResult(int statusCode, string statusDescription)

{

StatusCode = statusCode;

StatusDescription = statusDescription;

}

public int StatusCode { get; private set; }

public string StatusDescription { get; private set; }

public override void ExecuteResult(ControllerContext context)

{

if (context == null)

{

throw new ArgumentNullException("context");

}

context.HttpContext.Response.StatusCode = StatusCode;

if (StatusDescription != null)

{

context.HttpContext.Response.StatusDescription = StatusDescription;

}

}

  1. RedirectResult/RedirectToRouteResult

客户端的浏览器地址会变化

其作用与调用HttpResponse 的Redirect/RedirectPermanent 方法完全一致

暂时重定向和永久重定向有时又被称为"302 重定向"和"301 重定向"， 302 和301 表示响应的状态码。当我们调用HttpResponse 的RedirectIRedirectPermanent 方法时，除了会设置相应的响应状态码之外，还会将重定向的目标地址写入响应报头(Location) ，浏览器在接收到响应之后自动发起针对重定向目标地址的访问。

RedirectResult

public bool Permanent { get; private set; }

public string Url { get; private set; }

public override void ExecuteResult(ControllerContext context)

{

if (context == null)

{

throw new ArgumentNullException("context");

}

if (context.IsChildAction)

{

throw new InvalidOperationException(MvcResources.RedirectAction_CannotRedirectInChildAction);

}

string destinationUrl = UrlHelper.GenerateContentUrl(Url, context.HttpContext);

context.Controller.TempData.Keep();

if (Permanent)

{

context.HttpContext.Response.RedirectPermanent(destinationUrl, endResponse: false);

}

else

{

context.HttpContext.Response.Redirect(destinationUrl, endResponse: false);

}

}

RedirectToRouteResult

根据路由生成URL,

再进行重定向

public class RedirectToRouteResult : ActionResult
{ private RouteCollection _routes; public RedirectToRouteResult(RouteValueDictionary routeValues) : this(null, routeValues)
{ } public RedirectToRouteResult(string routeName, RouteValueDictionary routeValues) : this(routeName, routeValues, permanent: false)
{ } public RedirectToRouteResult(string routeName, RouteValueDictionary routeValues, bool permanent)
{ Permanent = permanent; RouteName = routeName ?? String.Empty; RouteValues = routeValues ?? new RouteValueDictionary(); } public bool Permanent { get; private set; } public string RouteName { get; private set; } public RouteValueDictionary RouteValues { get; private set; } internal RouteCollection Routes
{ get
{ if (_routes == null) { _routes = RouteTable.Routes; } return _routes; } set { _routes = value; } } public override void ExecuteResult(ControllerContext context)
{ if (context == null) { throw new ArgumentNullException("context"); } if (context.IsChildAction) { throw new InvalidOperationException(MvcResources.RedirectAction_CannotRedirectInChildAction); } string destinationUrl = UrlHelper.GenerateUrl(RouteName, null /* actionName */, null /* controllerName */, RouteValues, Routes, context.RequestContext, false /* includeImplicitMvcValues */); if (String.IsNullOrEmpty(destinationUrl)) { throw new InvalidOperationException(MvcResources.Common_NoRouteMatched); } context.Controller.TempData.Keep(); if (Permanent) { context.HttpContext.Response.RedirectPermanent(destinationUrl, endResponse: false); } else { context.HttpContext.Response.Redirect(destinationUrl, endResponse: false); } }}

ViewResult和ViewEngine

  1. View引擎中的View

IView

public interface IView

{

void Render(ViewContext viewContext, TextWriter writer);

}

ViewContext

  1. ViewEngine

IViewEngine

public interface IViewEngine

{

ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache);

ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache);

void ReleaseView(ControllerContext controllerContext, IView view);

}

ViewEngineResult

public class ViewEngineResult
{ public ViewEngineResult(IEnumerable<string> searchedLocations)
{ if (searchedLocations == null) { throw new ArgumentNullException("searchedLocations"); } SearchedLocations = searchedLocations; } public ViewEngineResult(IView view, IViewEngine viewEngine)
{ if (view == null) { throw new ArgumentNullException("view"); } if (viewEngine == null) { throw new ArgumentNullException("viewEngine"); } View = view; ViewEngine = viewEngine; } public IEnumerable<string> SearchedLocations { get; private set; } public IView View { get; private set; } public IViewEngine ViewEngine { get; private set; }}

ViewEngines

public static class ViewEngines
{ private static readonly ViewEngineCollection _engines = new ViewEngineCollection{new WebFormViewEngine(),new RazorViewEngine(),}; public static ViewEngineCollection Engines
{ get { return _engines; } }}

ViewEngineCollection

ViewEngineCollection 同样定义了FindViewlF indPartialView 方法用于获取指定名称的View 和分部View

public class ViewEngineCollection : Collection<IViewEngine>
{ private IResolver<IEnumerable<IViewEngine>> _serviceResolver; public ViewEngineCollection()
{ _serviceResolver = new MultiServiceResolver<IViewEngine>(() => Items); } public ViewEngineCollection(IList<IViewEngine> list) : base(list)
{ _serviceResolver = new MultiServiceResolver<IViewEngine>(() => Items); } public virtual ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName)
{ if (controllerContext == null) { throw new ArgumentNullException("controllerContext"); } if (String.IsNullOrEmpty(partialViewName)) { throw new ArgumentException(MvcResources.Common_NullOrEmpty, "partialViewName"); } return Find(e => e.FindPartialView(controllerContext, partialViewName, true), e => e.FindPartialView(controllerContext, partialViewName, false)); } public virtual ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName)
{ if (controllerContext == null) { throw new ArgumentNullException("controllerContext"); } if (String.IsNullOrEmpty(viewName)) { throw new ArgumentException(MvcResources.Common_NullOrEmpty, "viewName"); } return Find(e => e.FindView(controllerContext, viewName, masterName, true), e => e.FindView(controllerContext, viewName, masterName, false)); }}

  1. ViewResult的执行

如果Action的返回值不是ActionResult,就创建ContentResult