https://learn.microsoft.com/zh-tw/dotnet/api/system.web.ui.webcontrols.gridviewrow.rowindex?view=netframework-4.8.1&redirectedfrom=MSDN
GridViewRow.RowIndex Property (System.Web.UI.WebControls) | Microsoft Learn
Gets the index of the GridViewRow object in the Rows collection of a GridView control.
property systemweb uimicrosoftlearn