问从datatable中删除重复项的最佳方法是什么？

EN

// Fill the DataSet.
DataSet ds = new DataSet();
ds.Locale = CultureInfo.InvariantCulture;
FillDataSet(ds);

List<DataRow> rows = new List<DataRow>();

DataTable contact = ds.Tables["Contact"];

// Get 100 rows from the Contact table.
IEnumerable<DataRow> query = (from c in contact.AsEnumerable()
                              select c).Take(100);

DataTable contactsTableWith100Rows = query.CopyToDataTable();

// Add 100 rows to the list.
foreach (DataRow row in contactsTableWith100Rows.Rows)
    rows.Add(row);

// Create duplicate rows by adding the same 100 rows to the list.
foreach (DataRow row in contactsTableWith100Rows.Rows)
    rows.Add(row);

DataTable table =
    System.Data.DataTableExtensions.CopyToDataTable<DataRow>(rows);

// Find the unique contacts in the table.
IEnumerable<DataRow> uniqueContacts =
    table.AsEnumerable().Distinct(DataRowComparer.Default);

Console.WriteLine("Unique contacts:");
foreach (DataRow uniqueContact in uniqueContacts)
{
    Console.WriteLine(uniqueContact.Field<Int32>("ContactID"));
}

public class MyRowComparer : IEqualityComparer<DataRow>
{

    public bool Equals(DataRow x, DataRow y)
    {
        return (x.Field<int>("ID") == y.Field<int>("ID")) &&
            string.Compare(x.Field<string>("Name"), y.Field<string>("Name"), true) == 0 &&
          ... // extend this to include all your 4 keys...
    }

    public int GetHashCode(DataRow obj)
    {
        return obj.Field<int>("ID").GetHashCode() ^ obj.Field<string>("Name").GetHashCode() etc.
    }
}

var uniqueRows = myTable.AsEnumerable().Distinct(MyRowComparer);