MVC防止F5刷新重复提交数据

Controller代码如下：

//
        // GET: /Home/
        [HttpGet, ImportModelStateFromTempData]
        public ActionResult Register()
        {
            return View();
        }
        [HttpPost, ExportModelStateToTempData]
        public ActionResult RegisterProcess(Models.RegisterModel registerModel)
        {
            if (ModelState.IsValid)
            {
                return RedirectToAction("RegisterSuccess");
            }
            return RedirectToAction("Register");
        }
        [HttpGet]
        public ActionResult RegisterSuccess()
        {
            return View();
        }

上面的ImportModelStateFromTempData和ExportModelStateToTempData是ActionFilter

是为了解决Redirect不能保存Model的验证错误的问题.

实现的基本原理是通过ExportModelStateToTempData把Model的验证错误存放到TempData中, 

通过ImportModelStateFromTempData从TempData中把验证错误导入.

View代码是:

@using (Html.BeginForm("RegisterProcess", "Home"))
{
    <fieldset>
        <legend>Register</legend>
        @Html.ValidationSummary(true)
        <ol>
            <li>
                @Html.LabelFor(m => m.NickName)
                @Html.TextBoxFor(m => m.NickName)
                @Html.ValidationMessageFor(m => m.NickName)
            </li>
            <li>
                @Html.LabelFor(m => m.Email)
                @Html.TextBoxFor(m => m.Email)
                @Html.ValidationMessageFor(m => m.Email)
            </li>
        </ol>
        <input type="submit" value="Sumbit" />
    </fieldset>
}

ImportModelStateFromTempData和ExportModelStateToTempData的实现代码如下:

using System.Web.Mvc;

namespace MVCFormValiation.Filters
{
    public abstract class ModelStateTempDataTransfer : ActionFilterAttribute
    {
        protected static readonly string Key = typeof(ModelStateTempDataTransfer).FullName;
    }

    public class ExportModelStateToTempData : ModelStateTempDataTransfer
    {
        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            //Only export when ModelState is not valid
            if (!filterContext.Controller.ViewData.ModelState.IsValid)
            {
                //Export if we are redirecting
                if ((filterContext.Result is RedirectResult) || (filterContext.Result is RedirectToRouteResult))
                {
                    filterContext.Controller.TempData[Key] = filterContext.Controller.ViewData.ModelState;
                }
            }

            base.OnActionExecuted(filterContext);
        }
    }

    public class ImportModelStateFromTempData : ModelStateTempDataTransfer
    {
        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            var modelState = filterContext.Controller.TempData[Key] as ModelStateDictionary;

            if (modelState != null)
            {
                //Only Import if we are viewing
                if (filterContext.Result is ViewResult)
                {
                    filterContext.Controller.ViewData.ModelState.Merge(modelState);
                }
                else
                {
                    //Otherwise remove it.
                    filterContext.Controller.TempData.Remove(Key);
                }
            }

            base.OnActionExecuted(filterContext);
        }
    }
}