ModelStateDictionary不包含CopyTo的定义

本文关键字:定义 CopyTo 包含 ModelStateDictionary | 更新日期: 2023-09-27 17:55:02

.NET Core RC 1(完整的。NET框架)为我工作如下代码:

using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNet.Mvc;
using Microsoft.AspNet.Mvc.Filters;
using Microsoft.AspNet.Mvc.ModelBinding;
using Newtonsoft.Json;
namespace MyProject.Classes.Filters.ModelState
{
    public class SetTempDataModelStateAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            base.OnActionExecuted(filterContext);
            var controller = filterContext.Controller as Controller;
            if (controller != null)
            {
                var modelState = controller.ViewData.ModelState;
                if (modelState != null)
                {
                    var dictionary = new KeyValuePair<string, ModelStateEntry>[modelState.Count];
                    modelState.CopyTo(dictionary, 0);
                    var listError = dictionary.ToDictionary(m => m.Key, m => m.Value.Errors.Select(s => s.ErrorMessage).FirstOrDefault(s => s != null));
                    controller.TempData["ModelState"] = JsonConvert.SerializeObject(listError);
                }
            }
        }
    }
}

但是在ASP。.NET Core 1.0(完整的。NET框架),出现错误:

using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Newtonsoft.Json;
namespace MyProject.Models.ModelState
{
    public class SetTempDataModelStateAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuted(ActionExecutedContext filterContext)
        {
            base.OnActionExecuted(filterContext);
            var controller = filterContext.Controller as Controller;
            if (controller != null)
            {
                var modelState = controller.ViewData.ModelState;
                if (modelState != null)
                {
                    var dictionary = new KeyValuePair<string, ModelStateEntry>[modelState.Count];
                    modelState.CopyTo(dictionary, 0);
                    modelState = dictionary.[0];
                    var listError = dictionary.ToDictionary(m => m.Key, m => m.Value.Errors.Select(s => s.ErrorMessage).FirstOrDefault(s => s != null));
                    controller.TempData["ModelState"] = JsonConvert.SerializeObject(listError);
                }
            }
        }
    }
}

'ModelStateDictionary'不包含'CopyTo'和的定义没有扩展方法'CopyTo'接受类型的第一个参数可以找到'ModelStateDictionary'(您是否缺少一个using指令还是程序集引用?)

也许我需要将新的引用连接到ASP中不需要的程序集。. NET Core RC 1?

ModelStateDictionary不包含CopyTo的定义

ModelStateDictionary没有实现IDictionary<,>,因此没有CopyTo方法。在您的情况下,您可以将代码替换为

var listErrorr = modelState.ToDictionary(
  m => m.Key, 
  m => m.Value.Errors
    .Select(s => s.ErrorMessage)
    .FirstOrDefault(s => s != null)
); 

,这应该在功能上等同于您在原始代码片段中所做的。