未将对象引用设置为对象的实例

我有一个web应用程序，仅用于保存上传的视频文件的路径到sqlserver database.i在应用程序中有一个bussiness logicslayer。未将对象引用设置为对象的实例

我使用的是asp.net/vb.net。我把这个在BLL与存储过程的连接，

Dim Db As Database = DatabaseFactory.CreateDatabase()

有that--

object reference not set to an instance of an object

一个错误，如果任何人知道，请帮助我。

这里是堆栈跟踪：的对象意味着有被使用之前该wasnt实例化的引用不设置到一个实例

[NullReferenceException: Object reference not set to an instance of an object.] 
Microsoft.Practices.EnterpriseLibrary.Data.DatabaseConfigurationView.get_DefaultName() +38 
Microsoft.Practices.EnterpriseLibrary.Data.DatabaseMapper.MapName(String name, IConfigurationSource configSource) +65 
Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder.ConfigurationNameMappingStrategy.BuildUp(IBuilderContext context, Type t, Object existing, String id) +122 
Microsoft.Practices.ObjectBuilder.BuilderBase`1.DoBuildUp(IReadWriteLocator locator, Type typeToBuild, String idToBuild, Object existing, PolicyList[] transientPolicies) +316 
Microsoft.Practices.ObjectBuilder.BuilderBase`1.BuildUp(IReadWriteLocator locator, Type typeToBuild, String idToBuild, Object existing, PolicyList[] transientPolicies) +168 
Microsoft.Practices.ObjectBuilder.BuilderBase`1.BuildUp(IReadWriteLocator locator, String idToBuild, Object existing, PolicyList[] transientPolicies) +104 
Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder.EnterpriseLibraryFactory.BuildUp(IReadWriteLocator locator, IConfigurationSource configurationSource) +228 
Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder.EnterpriseLibraryFactory.BuildUp(IConfigurationSource configurationSource) +65 
Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder.NameTypeFactoryBase`1.CreateDefault() +72 
Microsoft.Practices.EnterpriseLibrary.Data.DatabaseFactory.CreateDatabase() +86 
Uploader.BllUpdate.SaveFileDetails() in D:\Developers\Sinoy\uploader\Uploader\Uploader\BLL\BllUpdate.vb:37 
Uploader.Upload.UploadBtn_Click(Object sender, EventArgs e) in D:\Developers\Sinoy\uploader\Uploader\Uploader\Forms\Upload.aspx.vb:17 
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105 
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107 
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7 
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11 
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33 
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102

来源

2009-10-29 user85511

使用所使用的技术标记您的问题。这看起来可能是视觉基础，但我不知道是什么样的。你现在不会得到答案。 – 2009-10-29 05:23:15

可能的重复[什么是NullReferenceException，我该如何解决它？]（http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it） – Plutonix 2014-10-15 22:25:56