<asp:LinqDataSource 

  ContextTypeName="string"

  TableName="Products"

  EnableUpdate="true"

  EnableInsert="true"

  EnableDelete="true"

  ID="LinqDataSource1"

  runat="server">

</asp:LinqDataSource>

<asp:DetailsView

  DataSourceID="LinqDataSource1"

  DataKeyNames="ProductID"

  AutoGenerateEditButton="true"

  AutoGenerateDeleteButton="true"

  AutoGenerateInsertButton="true"

  AllowPaging="true"

  ID="DetailsView1"

  runat="server">

</asp:DetailsView>

谁能帮我解答一下？小弟实在看不透了，ContextTypeName="string"这句话什么意思啊？