DataTableReader Konstruktor

Definisi

Ruang nama:

System.Data

Rakitan:

System.Data.Common.dll

Menginisialisasi instans baru kelas DataTableReader.

Overload

DataTableReader(DataTable)	Menginisialisasi instans DataTableReader baru kelas dengan menggunakan data dari yang disediakan DataTable.
DataTableReader(DataTable[])	Menginisialisasi instans DataTableReader baru kelas menggunakan array DataTable objek yang disediakan.

DataTableReader(DataTable)

Sumber:

DataTableReader.cs

Menginisialisasi instans DataTableReader baru kelas dengan menggunakan data dari yang disediakan DataTable.

public:
 DataTableReader(System::Data::DataTable ^ dataTable);

public DataTableReader (System.Data.DataTable dataTable);

new System.Data.DataTableReader : System.Data.DataTable -> System.Data.DataTableReader

Public Sub New (dataTable As DataTable)

Parameter

dataTable

DataTable

dari DataTable mana baru DataTableReader mendapatkan tataan hasilnya.

DataTableReader(DataTable[])

Sumber:

DataTableReader.cs

Menginisialisasi instans DataTableReader baru kelas menggunakan array DataTable objek yang disediakan.

public:
 DataTableReader(cli::array <System::Data::DataTable ^> ^ dataTables);

public DataTableReader (System.Data.DataTable[] dataTables);

new System.Data.DataTableReader : System.Data.DataTable[] -> System.Data.DataTableReader

Public Sub New (dataTables As DataTable())

Parameter

dataTables

DataTable[]

Array DataTable objek yang memasok hasil untuk objek baru DataTableReader .

Contoh

Dalam contoh berikut, metode TestConstructor membuat dua DataTable instans. Untuk menunjukkan konstruktor ini untuk DataTableReader kelas , sampel membuat baru DataTableReader berdasarkan array yang berisi dua DataTables, dan melakukan operasi sederhana, mencetak konten dari beberapa kolom pertama ke jendela konsol. Untuk menguji aplikasi ini, buat aplikasi Konsol baru, dan tempelkan kode sampel ke dalam file yang baru dibuat.

private static void TestConstructor()
{
    // Create two data adapters, one for each of the two
    // DataTables to be filled.
    DataTable customerDataTable = GetCustomers();
    DataTable productDataTable = GetProducts();

    // Create the new DataTableReader.
    using (DataTableReader reader = new DataTableReader(
               new DataTable[] { customerDataTable, productDataTable }))
    {
        // Print the contents of each of the result sets.
        do
        {
            PrintColumns(reader);
        } while (reader.NextResult());
    }

    Console.WriteLine("Press Enter to finish.");
    Console.ReadLine();
}

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 DataTable GetProducts()
{
    // Create sample Products 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, "Wireless Network Card" });
    table.Rows.Add(new object[] { 2, "Hard Drive" });
    table.Rows.Add(new object[] { 3, "Monitor" });
    table.Rows.Add(new object[] { 4, "CPU" });
    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();
    }
}

Private Sub TestConstructor()
   ' Create two data adapters, one for each of the two
   ' DataTables to be filled.
   Dim customerDataTable As DataTable = GetCustomers()
   Dim productDataTable As DataTable = GetProducts()

   ' Create the new DataTableReader.
   Using reader As New DataTableReader( _
      New DataTable() {customerDataTable, productDataTable})

      ' Print the contents of each of the result sets.
      Do
         PrintColumns(reader)
      Loop While reader.NextResult()
   End Using

   Console.WriteLine("Press Enter to finish.")
   Console.ReadLine()

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 Function GetProducts() As DataTable
   ' Create sample Products 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, "Wireless Network Card"})
   table.Rows.Add(New Object() {2, "Hard Drive"})
   table.Rows.Add(New Object() {3, "Monitor"})
   table.Rows.Add(New Object() {4, "CPU"})
   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

Jendela Konsol menampilkan hasil berikut:

1 Mary  
2 Andy  
3 Peter  
4 Russ  
1 Wireless Network Card  
2 Hard Drive  
3 Monitor  
4 CPU  

Keterangan

Jika Anda harus membuat DataTableReader berdasarkan semua atau subset tabel dalam tertentuDataSet, panggil DataSetmetode .CreateDataReader Jika Anda ingin membuat instans baru DataTableReader berdasarkan sekelompok DataTable instans yang tidak terkait, gunakan konstruktor ini. Anda juga dapat memanfaatkan konstruktor ini untuk mengatur ulang urutan DataTables dalam DataTableReader, jika pemesanan mereka dalam sumbernya DataSet tidak memenuhi kebutuhan Anda.