DataSet.Relations 属性

定义

命名空间:
System.Data
程序集:
System.Data.Common.dll
程序集:
netstandard.dll
程序集:
System.Data.dll

获取用于将表链接起来并允许从父表浏览到子表的关系的集合。Gets the collection of relations that link tables and allow navigation from parent tables to child tables.

public:
 property System::Data::DataRelationCollection ^ Relations { System::Data::DataRelationCollection ^ get(); };
public System.Data.DataRelationCollection Relations { get; }
[System.Data.DataSysDescription("DataSetRelationsDescr")]
public System.Data.DataRelationCollection Relations { get; }
member this.Relations : System.Data.DataRelationCollection
[<System.Data.DataSysDescription("DataSetRelationsDescr")>]
member this.Relations : System.Data.DataRelationCollection
Public ReadOnly Property Relations As DataRelationCollection

属性值

DataRelationCollection

一个包含 DataRelationCollection 对象集合的 DataRelation。A DataRelationCollection that contains a collection of DataRelation objects. 如果 DataRelation 对象不存在，将返回空集合。An empty collection is returned if no DataRelation objects exist.

属性
DataSysDescriptionAttribute

示例

下面的示例通过属性输出所有子表的列名称 Relations 。The following example prints the column name of all child tables through the Relations property.

Private Sub PrintChildRelationRows()
   ' Declare variable to hold the row values.
   Dim rowValues As String
   Dim dataSet As DataSet

   ' Get the DataSet of a DataGrid that is displaying data 
   ' of at least two tables.
   Dim table As DataTable = CType(DataGrid1.DataSource, DataTable)

   ' Navigate using the Relations.
   Dim relation As DataRelation
   Dim row As DataRow
   Dim column As DataColumn

   ' Print the names of each column in each table.
   For Each relation In dataSet.Relations
      For Each column in relation.ChildTable.Columns
          rowValues &= column.ColumnName & " "
      Next
    Next

    ' Display results.
    Console.WriteLine(rowValues)
   End Sub

适用于