有人能给我一个简洁的定义吗? ModelState在Asp.net MVC中的作用(或者一个链接)。特别是,我需要知道在什么情况下调用ModelState.Clear()
是必要的或可取的。
位是开放式的,嗯,...抱歉,我想告诉你我到底在做什么可能会有帮助:
我在一个名为"Page“的控制器上执行了一个编辑操作。当我第一次看到用于更改页面详细信息的表单时,一切都正常加载(绑定到"MyCmsPage“对象)。然后单击一个按钮,该按钮为MyCmsPage对象的一个字段(MyCmsPage.SeoTitle
)生成值。它生成fine并更新对象,然后我返回带有新修改的页面对象的操作结果,并期望更新相关的文本框(使用<%= Html.TextBox("seoTitle", page.SeoTitle)%>
呈现)……但是遗憾的是,它显示了加载的旧模型的值。
我已经通过使用ModelState.Clear()
解决了这个问题,但我需要知道它为什么/如何工作,所以我不是盲目地做它。
PageController:
[AcceptVerbs("POST")]
public ActionResult Edit(MyCmsPage page, string submitButton)
{
// add the seoTitle to the current page object
page.GenerateSeoTitle();
// why must I do this?
ModelState.Clear();
// return the modified page object
return View(page);
}
Aspx:
<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MyCmsPage>" %>
....
<div class="c">
<label for="seoTitle">
Seo Title</label>
<%= Html.TextBox("seoTitle", page.SeoTitle)%>
<input type="submit" value="Generate Seo Title" name="submitButton" />
</div>
发布于 2015-02-18 23:50:30
通常,当您发现自己在与框架标准实践作斗争时,是时候重新考虑您的方法了。在本例中,是指ModelState的行为。例如,当您不想在POST之后使用模型状态时,可以考虑重定向到get。
[HttpPost]
public ActionResult Edit(MyCmsPage page, string submitButton)
{
if (ModelState.IsValid) {
SomeRepository.SaveChanges(page);
return RedirectToAction("GenerateSeoTitle",new { page.Id });
}
return View(page);
}
public ActionResult GenerateSeoTitle(int id) {
var page = SomeRepository.Find(id);
page.GenerateSeoTitle();
return View("Edit",page);
}
编辑以回答文化评论:
下面是我用来处理多文化MVC应用程序的代码。首先是路由处理器子类:
public class SingleCultureMvcRouteHandler : MvcRouteHandler {
protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
{
var culture = requestContext.RouteData.Values["culture"].ToString();
if (string.IsNullOrWhiteSpace(culture))
{
culture = "en";
}
var ci = new CultureInfo(culture);
Thread.CurrentThread.CurrentUICulture = ci;
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(ci.Name);
return base.GetHttpHandler(requestContext);
}
}
public class MultiCultureMvcRouteHandler : MvcRouteHandler
{
protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
{
var culture = requestContext.RouteData.Values["culture"].ToString();
if (string.IsNullOrWhiteSpace(culture))
{
culture = "en";
}
var ci = new CultureInfo(culture);
Thread.CurrentThread.CurrentUICulture = ci;
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(ci.Name);
return base.GetHttpHandler(requestContext);
}
}
public class CultureConstraint : IRouteConstraint
{
private string[] _values;
public CultureConstraint(params string[] values)
{
this._values = values;
}
public bool Match(HttpContextBase httpContext,Route route,string parameterName,
RouteValueDictionary values, RouteDirection routeDirection)
{
// Get the value called "parameterName" from the
// RouteValueDictionary called "value"
string value = values[parameterName].ToString();
// Return true is the list of allowed values contains
// this value.
return _values.Contains(value);
}
}
public enum Culture
{
es = 2,
en = 1
}
这是我如何布线的路线。在创建路由之后,我在我的子代理(example.com/subagent1、example.com/subagent2等)前面加上了区域性代码。如果您只需要区域性,只需从路由处理程序和路由中删除子代理。
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.IgnoreRoute("Content/{*pathInfo}");
routes.IgnoreRoute("Cache/{*pathInfo}");
routes.IgnoreRoute("Scripts/{pathInfo}.js");
routes.IgnoreRoute("favicon.ico");
routes.IgnoreRoute("apple-touch-icon.png");
routes.IgnoreRoute("apple-touch-icon-precomposed.png");
/* Dynamically generated robots.txt */
routes.MapRoute(
"Robots.txt", "robots.txt",
new { controller = "Robots", action = "Index", id = UrlParameter.Optional }
);
routes.MapRoute(
"Sitemap", // Route name
"{subagent}/sitemap.xml", // URL with parameters
new { subagent = "aq", controller = "Default", action = "Sitemap"}, new[] { "aq3.Controllers" } // Parameter defaults
);
routes.MapRoute(
"Rss Feed", // Route name
"{subagent}/rss", // URL with parameters
new { subagent = "aq", controller = "Default", action = "RSS"}, new[] { "aq3.Controllers" } // Parameter defaults
);
/* remap wordpress tags to mvc blog posts */
routes.MapRoute(
"Tag", "tag/{title}",
new { subagent = "aq", controller = "Default", action = "ThreeOhOne", id = UrlParameter.Optional}, new[] { "aq3.Controllers" }
).RouteHandler = new MultiCultureMvcRouteHandler(); ;
routes.MapRoute(
"Custom Errors", "Error/{*errorType}",
new { controller = "Error", action = "Index", id = UrlParameter.Optional}, new[] { "aq3.Controllers" }
);
/* dynamic images not loaded from content folder */
routes.MapRoute(
"Stock Images",
"{subagent}/Images/{*filename}",
new { subagent = "aq", controller = "Image", action = "Show", id = UrlParameter.Optional, culture = "en"}, new[] { "aq3.Controllers" }
);
/* localized routes follow */
routes.MapRoute(
"Localized Images",
"Images/{*filename}",
new { subagent = "aq", controller = "Image", action = "Show", id = UrlParameter.Optional}, new[] { "aq3.Controllers" }
).RouteHandler = new MultiCultureMvcRouteHandler();
routes.MapRoute(
"Blog Posts",
"Blog/{*postname}",
new { subagent = "aq", controller = "Blog", action = "Index", id = UrlParameter.Optional}, new[] { "aq3.Controllers" }
).RouteHandler = new MultiCultureMvcRouteHandler();
routes.MapRoute(
"Office Posts",
"Office/{*address}",
new { subagent = "aq", controller = "Offices", action = "Address", id = UrlParameter.Optional }, new[] { "aq3.Controllers" }
).RouteHandler = new MultiCultureMvcRouteHandler();
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { subagent = "aq", controller = "Home", action = "Index", id = UrlParameter.Optional }, new[] { "aq3.Controllers" } // Parameter defaults
).RouteHandler = new MultiCultureMvcRouteHandler();
foreach (System.Web.Routing.Route r in routes)
{
if (r.RouteHandler is MultiCultureMvcRouteHandler)
{
r.Url = "{subagent}/{culture}/" + r.Url;
//Adding default culture
if (r.Defaults == null)
{
r.Defaults = new RouteValueDictionary();
}
r.Defaults.Add("culture", Culture.en.ToString());
//Adding constraint for culture param
if (r.Constraints == null)
{
r.Constraints = new RouteValueDictionary();
}
r.Constraints.Add("culture", new CultureConstraint(Culture.en.ToString(), Culture.es.ToString()));
}
}
}
https://stackoverflow.com/questions/1775170
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