ActionResult是一个抽象类：

public abstract class ActionResult  
{  
    public abstract void ExecuteResult(ControllerContext context);  
}

ActionResult的实现类都是通过操作Response对象，实现不同输出

ActionResult的实现类：

JsonResult：

默认情况下禁止Get访问，所以Get请求需要加AllowGet参数　　

response.ContentType = "application/json";
JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();
javaScriptSerializer.Serialize(Data)

ContentResult：

response.Write(Content);

EmptyResult：

什么都不返回~

RedirectResult：

context.HttpContext.Response.Redirect(url, false);

NotFound：

context.HttpContext.Response.StatusCode = ;

HttpStatusCodeResult：同上

HttpUnauthorizedResult：未授权，同上

FileResult：文件，重载

//字节数组
response.OutputStream.Write(FileContents, , FileContents.Length);

//流
Stream outputStream = response.OutputStream;
using (FileStream)
{
byte[] buffer = new byte[];
while (true)
{
int num = FileStream.Read(buffer, , );
if (num != )
{
outputStream.Write(buffer, , num);
continue;
}
break;
}
}

JavaScriptResult：

HttpResponseBase response = context.HttpContext.Response;
response.ContentType = "application/x-javascript";
if (Script != null)
{
　　response.Write(Script);
}

ViewResult

根据视图名称获取视图类，视图类是WebViewPage类的子类，实例化并传变量(ViewData、Model..)，调用视图类的RenderView()方法，将内容写入output流中