DataTable.CreateDataReader 方法

定义

命名空间:

System.Data

程序集:

System.Data.Common.dll

Source:

DataTable.cs

返回与此 DataTable 内的数据对应的 DataTableReader。

C#

public System.Data.DataTableReader CreateDataReader ();

返回

DataTableReader

DataTableReader 包含一个对应于源 DataTable 实例的结果集。

示例

以下控制台应用程序创建一个 DataTable 实例。 然后该示例将已填充的 DataTable 传递到调用 CreateDataReader 方法（可循环访问 DataTableReader 中包含的结果）的过程。

C#

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();
    }
}

该示例在控制台窗口中显示以下输出：

1 Mary

2 Andy

3 Peter

4 Russ

适用于

另请参阅

• CreateDataReader()
• DataTables