C# Asp.net mvc - 从自定义操作过滤器访问视图模型
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Asp.net mvc - Accessing view Model from a custom Action filter
提问by ebrown
I am trying to access the Model data passed to the view in the action filter OnActionExecuted. Does anyone know if this is possible?
我正在尝试访问传递给操作过滤器 OnActionExecuted 中的视图的模型数据。有谁知道这是否可能？
I am trying to do something like this:
我正在尝试做这样的事情：
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
//get model data
//...
sitemap.SetCurrentNode(model.Name);
}
Any advice?
有什么建议吗？
采纳答案by Steven Lyons
The model is at:
该模型位于：
filterContext.Controller.ViewData.Model
回答by gustavocs
I don't know why but filterContext.Controller.ViewData.Modelis always null even when the model bind is executed before OnActionExecuted. I found a solution using the OnModelUpdatedevent to set that property before.
我不知道为什么但filterContext.Controller.ViewData.Model即使模型绑定在OnActionExecuted. 我之前找到了使用OnModelUpdated事件设置该属性的解决方案。
I have the model binder:
我有模型活页夹：
public class CustomModelBinder: DefaultModelBinder
{
protected override void OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
controllerContext.Controller.ViewData.Model = bindingContext.Model;
base.OnModelUpdated(controllerContext, bindingContext);
}
}
After that you need to set the default binder to your new model binder in Application_Start()section in Global.asax:
之后，您需要Application_Start()在 Global.asax 的部分中将默认绑定器设置为新模型绑定器：
ModelBinders.Binders.DefaultBinder = new CustomModelBinder();
Finally you can access your Modelin an ActionFilterAttribute:
最后你可以访问你Model的ActionFilterAttribute：
public class TraceLog : ActionFilterAttribute
{
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
//filterContext.Controller.ViewData.Model now isn't null
base.OnActionExecuted(filterContext);
}
}
回答by Matas Vaitkevicius
If you are getting null - as alternative to @Gustavo Clemente's answer you can try overriding OnActionExecutedand passing your viewModel into view in following way:
如果您获得 null - 作为@Gustavo Clemente 的答案的替代方案，您可以尝试OnActionExecuted通过以下方式覆盖您的 viewModel 并将其传递到视图中：
Action:
行动：
[Breadcrumb("Index")]
public ActionResult UnitIndex()
{
View(new Answers());
}
Attribute:
属性：
public class BreadcrumbAttribute : ActionFilterAttribute
{
public string Page { get; set; }
public BreadcrumbAttribute(string page)
{
Page = page;
}
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
var model = (IBreadcrumbs)filterContext.Controller.ViewData.Model;
model.Breadcrumbs = BreadcrumbHelper.GetBreadCrumbs(string.Format("{0}", filterContext.RouteData.DataTokens["area"]), Page);
}
}
回答by Safin Ahmed
In .Net Core you have an ActionArguments IDictionary on the context, with all the parameters from your method
在 .Net Core 中，上下文中有一个 ActionArguments IDictionary，包含方法中的所有参数
So if you have the following controller method
所以如果你有以下控制器方法
[HttpPost]
public void Post([FromBody]BaseRequest request)
{
}
You can access the field like so
您可以像这样访问该字段
public override void OnActionExecuting(ActionExecutingContext context)
{
var request = context.ActionArguments["request"] as BaseRequest;`
//do whatever,
}
回答by Arun Kumar A.J
Making the base.OnActionExecuted()call the last line of the method solved the 'Model being null' problem for me.
使得base.OnActionExecuted()调用该方法的最后一行解决了“模式被空”的问题对我来说。
(This is a comment to @Steven Lyons 's answer, but I'm posting as an answer because I can't comment.)
（这是对@Steven Lyons 的回答的评论，但我将其作为回答发布，因为我无法发表评论。）
