c# – Visual Studio 2015 LinqToExcel不起作用

发布时间：2020-12-15 20:56:36 所属栏目：百科来源：网络整理

导读：我有一个用VS2012编写的asp.net应用程序.在我搬到VS2015之前,我一直在使用 LinqToExcel而没有任何问题. 这是我的代码： var excel = new ExcelQueryFactory(fileName);var entriesQuery = from entry in excel.WorksheetVEntry(0) where entry.MovieTitle !=

我有一个用VS2012编写的asp.net应用程序.在我搬到VS2015之前,我一直在使用 LinqToExcel而没有任何问题.
这是我的代码：

var excel = new ExcelQueryFactory(fileName);
var entriesQuery = from entry in excel.Worksheet<VEntry>(0)
                                      where entry.MovieTitle != null
                                      select entry;

                var entries = entriesQuery.ToList();

VEntry类

public class VEntry
    {
        [ExcelColumn("id kolekcji")]
        [DefaultValue("")]
        public String CollectionId { get; set; }

        [ExcelColumn("nazwa kolekcji")]
        [DefaultValue("")]
        public String CollectionName { get; set; }

        [ExcelColumn("Tytu? serialu/serii/filmu")]
        [DefaultValue("")]
        public String MovieTitle { get; set; }

        [ExcelColumn("Tytu? odcinka")]
        [DefaultValue("")]
        public String EpisodeTitle { get; set; }

        [ExcelColumn("Sezon")]
        [DefaultValue("")]
        public String Season { get; set; }

        [ExcelColumn("nr odcinka")]
        [DefaultValue("")]
        public String EpisodeNumber { get; set; }

        [ExcelColumn("Start")]
        public DateTime StartDate { get; set; }

        [ExcelColumn("Koniec")]
        public DateTime EndDate { get; set; }

        [ExcelColumn("Kategoria tematyczna")]
        [DefaultValue("")]
        public String Category { get; set; }

        [ExcelColumn("Cena")]
        [DefaultValue("")]
        public String Price { get; set; }

        [ExcelColumn("kategoria wiekowa")]
        [DefaultValue("")]
        public String AgeCategory { get; set; }

        [ExcelColumn("Seria (0/1)")]
        [DefaultValue("")]
        public bool IsSeries { get; set; }

        [ExcelColumn("box set (0/1)")]
        [DefaultValue("")]
        public bool IsBoxSet { get; set; }

        [ExcelColumn("Ca?y sezon")]
        [DefaultValue("")]
        public bool IsFullSeason { get; set; }
    }

它在VS2012上运行良好.当我在VS2015中构建它时,我会在线上获得异常

var entries = entriesQuery.ToList();

:

Object must implement IConvertible.

   at System.Convert.ChangeType(Object value,Type conversionType,IFormatProvider provider)
   at LinqToExcel.Extensions.CommonExtensions.Cast(Object object,Type castType)
   at LinqToExcel.Extensions.CommonExtensions.Cast[T](Object object)
   at LinqToExcel.Extensions.CommonExtensions.IsNullValue(Expression exp)
   at LinqToExcel.Query.WhereClauseExpressionTreeVisitor.VisitBinaryExpression(BinaryExpression bExp)
   at LinqToExcel.Query.SqlGeneratorQueryModelVisitor.VisitWhereClause(WhereClause whereClause,QueryModel queryModel,Int32 index)
   at Remotion.Data.Linq.QueryModelVisitorBase.VisitBodyClauses(ObservableCollection`1 bodyClauses,QueryModel queryModel)
   at LinqToExcel.Query.SqlGeneratorQueryModelVisitor.VisitQueryModel(QueryModel queryModel)
   at LinqToExcel.Query.ExcelQueryExecutor.GetSqlStatement(QueryModel queryModel)
   at LinqToExcel.Query.ExcelQueryExecutor.ExecuteCollection[T](QueryModel queryModel)
   at Remotion.Data.Linq.Clauses.StreamedData.StreamedSequenceInfo.ExecuteQueryModel(QueryModel queryModel,IQueryExecutor executor)
   at Remotion.Data.Linq.QueryProviderBase.Execute[TResult](Expression expression)
   at Remotion.Data.Linq.QueryableBase`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Logic.Importers.VodImporter.VodImporter.Run(String fileName,Boolean publishAfterImport) in C:ncplusnplLogicImportersVodImporterVodImporter.cs:line 103
   at Website.sitecore_modules.Shell.Editors.VodImporterEditor.Page_Load(Object sender,EventArgs e)

但是当我在VS2012中构建它时,它再次起作用.可能有什么不对？我不知道.

编辑：在VS2013上也可以.

解决方法

我假设’MovieTitle’不接受模型中的空值.如果这是真的,请将您的where子句更改为以下内容.

var entriesQuery = from entry in excel.Worksheet<VEntry>(0)
                                  where entry.MovieTitle != string.Empty
                                  select entry;

（编辑：李大同）

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