DataTableCollection.RemoveAt(Int32) Metoda

Definice

Obor názvů:

System.Data

Sestavení:

System.Data.Common.dll

Zdroj:

DataTableCollection.cs

Odebere DataTable objekt v zadaném indexu z kolekce.

public:
 void RemoveAt(int index);

public void RemoveAt (int index);

member this.RemoveAt : int -> unit

Public Sub RemoveAt (index As Integer)

Parametry

index

Int32

Index objektu, který DataTable se má odebrat.

Výjimky

ArgumentException

Kolekce nemá tabulku v zadaném indexu.

Příklady

Následující příklad používá Contains metody a CanRemove k otestování, zda existuje tabulka s indexem 10. Pokud ano, zavolá se RemoveAt metoda k odebrání tabulky.

public static void DataTableCollectionRemoveAt()
{
    // Create a DataSet with two tables and then
    // remove the tables from the collection using RemoveAt.
    DataSet dataSet = new DataSet();

    // Create Customer table.
    DataTable customerTable = new DataTable("Customers");
    customerTable.Columns.Add("customerId",
        typeof(int)).AutoIncrement = true;
    customerTable.Columns.Add("name", typeof(string));
    customerTable.PrimaryKey = new DataColumn[] { customerTable.Columns["customerId"] };

    // Create Orders table.
    DataTable ordersTable = new DataTable("Orders");
    ordersTable.Columns.Add("orderId",
        typeof(int)).AutoIncrement = true;
    ordersTable.Columns.Add("customerId", typeof(int));
    ordersTable.Columns.Add("amount", typeof(double));
    ordersTable.PrimaryKey = new DataColumn[] { ordersTable.Columns["orderId"] };

    dataSet.Tables.AddRange(new DataTable[] { customerTable, ordersTable });

    // Remove all tables.
    // First check to see if the table can be removed,
    // then remove it.
    //
    // You cannot use a foreach when removing items
    // from a collection.
    while (dataSet.Tables.Count > 0)
    {
        DataTable table = dataSet.Tables[0];
        if (dataSet.Tables.CanRemove(table))
            dataSet.Tables.RemoveAt(0);
        Console.WriteLine("dataSet has {0} tables",
            dataSet.Tables.Count);
    }
}

Public Sub DataTableCollectionRemoveAt()
    ' Create a DataSet with two tables and then
    ' remove the tables from the collection using RemoveAt.
    Dim dataSet As New DataSet()

    ' Create Customer table.
    Dim customerTable As New DataTable("Customers")
    customerTable.Columns.Add("customerId", _
        GetType(Integer)).AutoIncrement = True
    customerTable.Columns.Add("name", GetType(String))
    customerTable.PrimaryKey = New DataColumn() _
        {customerTable.Columns("customerId")}

    ' Create Orders table.
    Dim ordersTable As New DataTable("Orders")
    ordersTable.Columns.Add("orderId", _
        GetType(Integer)).AutoIncrement = True
    ordersTable.Columns.Add("customerId", GetType(Integer))
    ordersTable.Columns.Add("amount", GetType(Double))
    ordersTable.PrimaryKey = New DataColumn() _
        {ordersTable.Columns("orderId")}

    dataSet.Tables.AddRange(New DataTable() _
        {customerTable, ordersTable})

    ' Remove all tables.
    ' First check to see if the table can be removed,
    ' then remove it.
    '
    ' You cannot use a foreach when removing items
    ' from a collection.
    Do While (dataSet.Tables.Count > 0)
        Dim table As DataTable = dataSet.Tables(0)
        If (dataSet.Tables.CanRemove(table)) Then
            dataSet.Tables.RemoveAt(0)
        End If
        Console.WriteLine("dataSet has {0} tables", _
            dataSet.Tables.Count)
    Loop
End Sub

Poznámky

Událost CollectionChanged nastane, když je tabulka úspěšně odebrána.

Viz také

• IndexOf(DataTable)
• Contains(String)