步驟1：於TABLE表內新增一欄位「ele」，選擇Double格式，並設定階層
Step 1：Add the field name you want, and select the “double” type. Then edit and set the elevation you need.
步驟2：選擇欲操作之圖層，點選右鍵「Properties」，選擇「Dispaly」，並將「Field」選至「ele」後，點選「Expression」
Step 2：
Select the layer you want to operate, and right-click select “Properties” and “Display”.
Below the "Display Expression ", “Field” select “ele” and click “Expression”.
步驟3：「Expression」方框下，選擇「ele」，點選確定即可
Step 3：Set “ele” in the smaller box below the “Expression”. And it’s down for click “OK”.
