<ComboBox Height="23" HorizontalAlignment="Right" Margin="0,43,140,0" Name="comboBox2" VerticalAlignment="Top" Width="169" IsEditable="True" IsTextSearchEnabled="True"/>

public void BindMedicalStoreComboBox(ComboBox comboBox1)
    {
        SqlDataAdapter da = new SqlDataAdapter("Select medical_store_id,m_store_name FROM medical_store", con);
        DataSet ds = new DataSet();
        da.Fill(ds, "medical_store");
        comboBox2.ItemsSource = ds.Tables[0].DefaultView;
        comboBox2.DisplayMemberPath = ds.Tables[0].Columns["m_store_name"].ToString();
        comboBox2.SelectedValuePath = ds.Tables[0].Columns["medical_store_id"].ToString();

    }