public abstract class ActionResult
{
public abstract void ExecuteResult(ControllerContext context);
}
- 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
-
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
-
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
- 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);
}
}
}
- 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,
}
- 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;
}
}
- 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
- View引擎中的View
IView
public interface IView
{
void Render(ViewContext viewContext, TextWriter writer);
}
ViewContext
- 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));
}
}
- ViewResult的执行
如果Action的返回值不是ActionResult,就创建ContentResult