c# - 设置 ItemsSource 时出现 System.NullReferenceException

Question

设置 ItemsSource (ADO.NET EF) 时出现 System.NullReferenceException

dataGrid.ItemsSource = OdbConnectHelper.entObj.работники.ToList();

我检查了 App.Config，一切似乎都正确连接

<add name="qualificationEntities" connectionString="metadata=res://*/db.qualification.csdl|res://*/db.qualification.ssdl|res://*/db.qualification.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=.\sqlexpress01;initial catalog=qualification;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" /><add name="DefaultConnection" connectionString="Data Source=.\sqlexpress01;Initial Catalog=qualification;Integrated Security=True" providerName="System.Data.SqlClient" />

可能是什么问题呢？

标签： c#databaseentity-frameworkentity-framework-6ado.net

Answer 1

我找到了解决方案。OdbConnectHelper.entObj = new qualificationEntities();初始化后忘记在 MainWindow中写入。