自动映射器显示错误“指定的演员表无效。”

Question

在将 DataTable 与模型映射时出错

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();
        }

错误的堆栈跟踪如下

       [InvalidCastException: Specified cast is not valid.]    DynamicCreate(IDataRecord ) +1673   

AutoMapper.Mappers.DataReaderMapper.Map(ResolutionContext 上下文， IMappingEngineRunner 映射器）+433
AutoMapper.MappingEngine.AutoMapper.IMappingEngineRunner.Map(ResolutionContext 上下文）+347

[AutoMapperMappingException: 试图将 System.Data.IDataReader 映射到 System.Collections.Generic.IList1[[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, Action1 选择）+353
AutoMapper.MappingEngine.Map(TSource 源) +564
AutoMapper.Mapper.Map(TSource 源) +461
SkillKindleAdmin.Controllers.FeedbackController.ExcelUpload(HttpPostedFileBase 文件）在 d:\Skill Online\trunk\SkillKindleAdmin\Controllers\FeedbackController.cs:57
lambda_method(闭包, ControllerBase, Object[]) +107
System.Web.Mvc.ActionMethodDispatcher.Execute（ControllerBase 控制器，Object[] 参数）+286
System.Web.Mvc.ReflectedActionDescriptor.Execute（ControllerContext 控制器上下文，IDictionary2 parameters) +655
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2 参数）+326
System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeSynchronousActionMethod（ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2 parameters) +317
System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +219 System.Web.Mvc.Async.<>c__DisplayClass81.b__7(IAsyncResult ) +275 System.Web.Mvc.Async.WrappedAsyncResult1.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.WrappedAsyncResult1.End() +328 System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, 对象标签) +492
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters（IAsyncResult asyncResult) +262
System.Web.Mvc.Async.c_DisplayClass2a.b_20() +203 System.Web.Mvc.Async.c_DisplayClass25.b_22(IAsyncResult asyncResult) +392 System.Web.Mvc.Async.WrappedAsyncResult1.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.WrappedAsyncResult1.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.c_DisplayClass4.b__3(IAsyncResult ar) +275 System.Web.Mvc.Async.WrappedAsyncResult1.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.WrappedAsyncResult1.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& completedSynchronously) +603

Answer 1

您确定数据读取器返回的列与对象 ExcelFeedbackRecord 中的属性字段完全匹配，包括大小写？ 如果不是，则必须在创建地图时添加配置。

Answer 2

问题是当我们用模型映射DataSet时，模型的所有属性都必须是字符串类型，然后你可以使用automapper的CustomTypeConversion方法。