DataTable.CreateDataReader Metode

Definisi

Ruang nama:

System.Data

Rakitan:

System.Data.Common.dll

Sumber:

DataTable.cs

Mengembalikan yang DataTableReader sesuai dengan data dalam ini DataTable.

public:
 System::Data::DataTableReader ^ CreateDataReader();

public System.Data.DataTableReader CreateDataReader ();

member this.CreateDataReader : unit -> System.Data.DataTableReader

Public Function CreateDataReader () As DataTableReader

Mengembalikan

DataTableReader

Yang DataTableReader berisi satu tataan hasil, sesuai dengan instans sumber DataTable .

Contoh

Aplikasi konsol berikut ini membuat instans DataTable. Contoh kemudian meneruskan DataTable yang diisi ke prosedur yang memanggil metode CreateDataReader, yang berulang melalui hasil yang terkandung dalam DataTableReader.

static void Main()
{
    TestCreateDataReader(GetCustomers());
    Console.WriteLine("Press any key to continue.");
    Console.ReadKey();
}

private static void TestCreateDataReader(DataTable dt)
{
    // Given a DataTable, retrieve a DataTableReader
    // allowing access to all the tables' data:
    using (DataTableReader reader = dt.CreateDataReader())
    {
        do
        {
            if (!reader.HasRows)
            {
                Console.WriteLine("Empty DataTableReader");
            }
            else
            {
                PrintColumns(reader);
            }
            Console.WriteLine("========================");
        } while (reader.NextResult());
    }
}

private static DataTable GetCustomers()
{
    // Create sample Customers table, in order
    // to demonstrate the behavior of the DataTableReader.
    DataTable table = new DataTable();

    // Create two columns, ID and Name.
    DataColumn idColumn = table.Columns.Add("ID", typeof(int));
    table.Columns.Add("Name", typeof(string));

    // Set the ID column as the primary key column.
    table.PrimaryKey = new DataColumn[] { idColumn };

    table.Rows.Add(new object[] { 1, "Mary" });
    table.Rows.Add(new object[] { 2, "Andy" });
    table.Rows.Add(new object[] { 3, "Peter" });
    table.Rows.Add(new object[] { 4, "Russ" });
    return table;
}

private static void PrintColumns(DataTableReader reader)
{
    // Loop through all the rows in the DataTableReader
    while (reader.Read())
    {
        for (int i = 0; i < reader.FieldCount; i++)
        {
            Console.Write(reader[i] + " ");
        }
        Console.WriteLine();
    }
}

Sub Main()
  TestCreateDataReader(GetCustomers())
  Console.WriteLine("Press any key to continue.")
  Console.ReadKey()
End Sub

Private Sub TestCreateDataReader(ByVal dt As DataTable)
  ' Given a DataTable, retrieve a DataTableReader
  ' allowing access to all the tables's data:
  Using reader As DataTableReader = dt.CreateDataReader()
    Do
      If Not reader.HasRows Then
        Console.WriteLine("Empty DataTableReader")
      Else
        PrintColumns(reader)
      End If
      Console.WriteLine("========================")
    Loop While reader.NextResult()
  End Using
End Sub

Private Function GetCustomers() As DataTable
  ' Create sample Customers table, in order
  ' to demonstrate the behavior of the DataTableReader.
  Dim table As New DataTable

   ' Create two columns, ID and Name.
  Dim idColumn As DataColumn = table.Columns.Add("ID", GetType(Integer))
  table.Columns.Add("Name", GetType(String))

  ' Set the ID column as the primary key column.
  table.PrimaryKey = New DataColumn() {idColumn}

  table.Rows.Add(New Object() {1, "Mary"})
  table.Rows.Add(New Object() {2, "Andy"})
  table.Rows.Add(New Object() {3, "Peter"})
  table.Rows.Add(New Object() {4, "Russ"})
  Return table
End Function

Private Sub PrintColumns( _
   ByVal reader As DataTableReader)

  ' Loop through all the rows in the DataTableReader.
  Do While reader.Read()
    For i As Integer = 0 To reader.FieldCount - 1
      Console.Write(reader(i).ToString() & " ")
    Next
    Console.WriteLine()
  Loop
End Sub

Contoh ini menampilkan output berikut di jendela konsol:

1 Mary

2 Andy

3 Peter

4 Russ

Lihat juga

• CreateDataReader()
• DataTables