A few days ago, the problem encountered when the DROPDOWNLIST binds the data, and it is always impossible to save the modified state. After recent programming, it is finally a higher a little aware of this issue. (Compared with my own words)
In ASP.NET, any content in the control tabby data is modified. You cannot call DATABIND before saving the database. So if there is Database if there is Database in the Page_Load event, you must put Database in IF (ISPostBack) so that the DataBind event is called only when the page is loaded first. Otherwise, you will submit the changes in the page first to call the content in the page_load event, so if you encounter DataBind, the data you modified is still restored. At this time, the saved program you wrote is executed, and it is saved at this time that there is no modified data. Leading to save failed.
