DataSet.OnRemoveTable(DataTable) 方法

定义

命名空间:

System.Data

程序集:

System.Data.Common.dll

程序集:

System.Data.dll

程序集:

netstandard.dll

当从 DataTable 中移除 DataSet 时发生。

protected public:
 virtual void OnRemoveTable(System::Data::DataTable ^ table);

protected:
 virtual void OnRemoveTable(System::Data::DataTable ^ table);

protected internal virtual void OnRemoveTable (System.Data.DataTable table);

protected virtual void OnRemoveTable (System.Data.DataTable table);

abstract member OnRemoveTable : System.Data.DataTable -> unit
override this.OnRemoveTable : System.Data.DataTable -> unit

Protected Friend Overridable Sub OnRemoveTable (table As DataTable)

Protected Overridable Sub OnRemoveTable (table As DataTable)

参数

table

DataTable

正在移除的 DataTable。

示例

下面的示例演示了一个派生自 DataSet 方法 OnRemoveTable 的类。该方法被重写。

public static void DemonstrateOnRemoveTable()
{
    DerivedDataSet dataSet = CreateDataSet();
    if(dataSet.Tables.Count > 0)
        dataSet.Tables.RemoveAt(0);
}

public class DerivedDataSet: DataSet
{
    protected override void OnRemoveTable(DataTable table)
    {
        Console.WriteLine(
            "The '{0}' DataTable has been removed from the DataSet",
            table.TableName);
    }
}

public static DerivedDataSet CreateDataSet()
{
    // Create a DataSet with one table containing two columns.
    DerivedDataSet derived = new DerivedDataSet();

    // Add table to DataSet.
    DataTable table = derived.Tables.Add("Items");

    // Add two columns.
    DataColumn column = table.Columns.Add("id", typeof(int));
    column.AutoIncrement = true;
    table.Columns.Add("item", typeof(int));

    // Set primary key.
    table.PrimaryKey = new DataColumn[] {table.Columns["id"]};

    return derived;
}

Public Shared Sub DemonstrateOnRemoveTable()
    Dim dataSet As DerivedDataSet = CreateDataSet()
    If dataSet.Tables.Count > 0 Then dataSet.Tables.RemoveAt(0)
End Sub

Public Class DerivedDataSet
    Inherits DataSet
    Protected Overrides Sub OnRemoveTable(table As DataTable)
        Console.WriteLine( _
            "The '{0}' DataTable has been removed from the DataSet", _
            table.TableName)
    End Sub
End Class

Public Shared Function CreateDataSet() As DerivedDataSet
    ' Create a DataSet with one table containing two columns.
    Dim derived As New DerivedDataSet()

    ' Add table to DataSet.
    Dim table As DataTable = derived.Tables.Add("Items")

    ' Add two columns.
    Dim column As DataColumn = table.Columns.Add("id", _
        Type.GetType("System.Int32"))
    column.AutoIncrement = True
    table.Columns.Add("item", Type.GetType("System.Int32"))

    ' Set primary key.
    table.PrimaryKey = New DataColumn() {table.Columns("id")}

    return derived
End Function

注解

可以通过子类重写此方法，以限制要删除的表。

另请参阅

• 在 ADO.NET 中使用数据集