asp.net MVC利用ActionFilterAttribute过滤关键字的方法

using System.Web.Mvc;
using TinyFrame.Plugin.StrongTyped.Models;

namespace TinyFrame.Plugin.StrongTyped
{
  public class FilterCharsAttribute : ActionFilterAttribute
  {
    protected string parameterName = "t";
    protected TestModel model;
    
 public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
      base.OnActionExecuting(filterContext);
      
   //No Parameters, will return directly.
      if(!filterContext.ActionParameters.ContainsKey(parameterName))
        return;
      
   var t = filterContext.ActionParameters[parameterName] as TestModel;
      
   //No Entity data, will return directly
      if (t == null)
        return;
      
   //Replace chars that should be filtered
      if (!string.IsNullOrEmpty(t.TName))
        t.TName = t.TName.Replace("<", "&lt").Replace(">", "&gt");
      if (!string.IsNullOrEmpty(t.TSite))
        t.TSite = t.TSite.Replace("<", "&lt").Replace(">", "&gt");
    }
  }
}

public ActionResult Index(TestModel t)
{
     ViewData["ConvertedModel"] = t;
     return View();
}

[ValidateInput(false)]
[FilterChars]
public ActionResult Index(TestModel t)
{
   ViewData["ConvertedModel"] = t;
   return View();
}