/// <summary>
        /// 初始化日期下拉列表
        /// </summary>
        private void SetDateList()
        {
            comboBox1.Items.Clear();
            DataTable table = MapDBClass.GetPropertyDateList(_MapId, _LayerId, _Object.ID);

            for (int i = 0; i < table.Rows.Count; i++)
            {
                comboBox1.Items.Add(table.Rows[i][0].ToString());
            }
            if (comboBox1.Items.Count > 0)
            {
                comboBox1.SelectedIndex = comboBox1.Items.Count - 1;
            }
            else
            {
                comboBox1_SelectedIndexChanged(null, null);
            }
        }