按日期过滤 dataGridView

您需要按日期进行过滤，表格通过以下代码填充：

    DataSet dataSet = new DataSet();
    OleDbDataAdapter dataAdapter = new OleDbDataAdapter();
    OleDbDataAdapter dataAdapter1 = new OleDbDataAdapter();

    string query = "select * from Договор";
    string query1 = "select * from Поставщики";

    conn = new OleDbConnection(conn_string);

    dataAdapter.SelectCommand = new OleDbCommand(query, conn);
    dataAdapter1.SelectCommand = new OleDbCommand(query1, conn);

    dataAdapter.TableMappings.Add("Table", "Договор");
    dataAdapter1.TableMappings.Add("Table", "Поставщики");

    dataAdapter.Fill(dataSet);
    dataAdapter1.Fill(dataSet);

    BindingSource dogSource = new BindingSource();
    dogSource.DataSource = dataSet;
    dogSource.DataMember = "Договор";
    dataGridView1.DataSource = dogSource;

    BindingSource postSource = new BindingSource();
    postSource.DataSource = dataSet;
    postSource.DataMember = "Поставщики";

    DataGridViewComboBoxColumn comboColumn = new DataGridViewComboBoxColumn();
    comboColumn.HeaderText = "Поставщики";
    comboColumn.DataSource = postSource;

    comboColumn.DataPropertyName = "Код поставщика";

    comboColumn.DisplayMember = "Название";

    comboColumn.ValueMember = "Код поставщика";

以前，我在任何地方都使用过过滤，

    DataView dv = new DataView(dt);
    dv.RowFilter = string.Format(" CONVERT([Дата заключения], 'System.DateTime') >= '{0:dd.MM.yyyy}' AND CONVERT([Дата заключения], 'System.DateTime') <= '{0:dd.MM.yyyy}'",
    dateTimePicker1.Value.ToShortDateString());;
    dataGridView1.DataSource=dv;

但现在这不起作用，很可能是因为 DataSource。不幸的是，我不是这方面的专家，我将不胜感激。