Question

我在使用模型

映射DataTable时遇到错误

这是我的代码

       if (file.ContentLength > 0)
        {
            var extension = Path.GetExtension(file.FileName);
            if (extension != null && extension.ToLower() != ".xlsx")
            {
                return "please upload file with extension .xlsx";
            }

            Stream stream = file.InputStream;
            IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);
            excelReader.IsFirstRowAsColumnNames = true;
            DataSet result = excelReader.AsDataSet();
            if (result.Tables.Count > 0)
            {
                Mapper.Reset();
                Mapper.CreateMap<IDataReader, ExcelFeedbackRecord>();

                var results = Mapper.Map<IDataReader, IList<ExcelFeedbackRecord>>(result.Tables[0].CreateDataReader());

            }
            return result.Tables[0].Rows.Count.ToString();
        }

错误的堆栈跟踪低于

       [InvalidCastException: Specified cast is not valid.]    DynamicCreate(IDataRecord ) +1673   
AutoMapper.Mappers.DataReaderMapper.Map（ResolutionContext context，   IMappingEngineRunner mapper）+433
  AutoMapper.MappingEngine.AutoMapper.IMappingEngineRunner.Map（ResolutionContext   上下文）+347

[AutoMapperMappingException：尝试将System.Data.IDataReader映射到   System.Collections.Generic.IList 1[[SkillKindle.BLL.Feedbacks.ExcelFeedbackRecord, SkillKindle.BLL, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]. Exception of type 'AutoMapper.AutoMapperMappingException' was thrown.] AutoMapper.MappingEngine.AutoMapper.IMappingEngineRunner.Map(ResolutionContext context) +433 AutoMapper.MappingEngine.Map(Object source, Type sourceType, Type destinationType, Action 1 opts）+353
  AutoMapper.MappingEngine.Map（TSource源码）+564
  AutoMapper.Mapper.Map（TSource源码）+461
  SkillKindleAdmin.Controllers.FeedbackController.ExcelUpload（HttpPostedFileBase   文件）在d：\技能   在线\干线\ SkillKindleAdmin \ \控制器FeedbackController.cs：57个
  lambda_method（Closure，ControllerBase，Object []）+ 107 7   System.Web.Mvc.ActionMethodDispatcher.Execute（ControllerBase   controller，Object []参数）+286
  System.Web.Mvc.ReflectedActionDescriptor.Execute（ControllerContext   controllerContext，IDictionary 2 parameters) +655 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary 2   参数）+326
  System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeSynchronousActionMethod（ControllerContext   controllerContext，ActionDescriptor actionDescriptor，IDictionary 2 parameters) +317 System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +219 System.Web.Mvc.Async.<>c__DisplayClass8 1.b__7（IAsyncResult）   ）+275 System.Web.Mvc.Async.WrappedAsyncResult 1.End() +328 System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +492 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +261 System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +268 System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +461 System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +235 System.Web.Mvc.Async.WrappedAsyncResult 1.End（）   +328 System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，Object tag）+492
  System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters（IAsyncResult的   asyncResult）+262
  System.Web.Mvc.Async＆LT;。＆以及c _DisplayClass2a.b_ 20（）   +203 System.Web.Mvc.Async。＆lt;＆gt; c _DisplayClass25.b_ 22（IAsyncResult   asyncResult）+392 System.Web.Mvc.Async.WrappedAsyncResult 1.End() +316 System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +387 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +285 System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +234 System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +275 System.Web.Mvc.Async.WrappedAsyncResult 1.End（）+333
  System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，   对象标签）+397
  System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，   对象标签）+266
  System.Web.Mvc.Controller.EndExecuteCore（IAsyncResult asyncResult）   +253 System.Web.Mvc.Async。＆lt;＆gt; c _DisplayClass4.b__3（IAsyncResult）   ar）+275 System.Web.Mvc.Async.WrappedAsyncResult 1.End() +333 System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +397 System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +266 System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +254 System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +226 System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +230 System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +275 System.Web.Mvc.Async.WrappedAsyncResult 1.End（）+333
  System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，   对象标签）+397
  System.Web.Mvc.Async.AsyncResultWrapper.End（IAsyncResult asyncResult，   对象标签）+266
  System.Web.Mvc.MvcHandler.EndProcessRequest（IAsyncResult asyncResult）   +255 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest（IAsyncResult）   结果）+225
  System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）   +1086 System.Web.HttpApplication.ExecuteStep（IExecutionStep step，Boolean＆amp; completedSynchronously）+603

Answer 1

您确定datareader返回的列与对象ExcelFeedbackRecord中的属性字段完全匹配，包括套管吗？如果不是，则在创建地图时必须添加配置。

Answer 2

问题是，当我们使用模型映射DataSet时，模型的所有属性必须只是字符串类型，然后你可以使用automapper的CustomTypeConversion方法。

automapper显示错误“指定的强制转换无效”。

2 个答案: