FindControl returns null in MasterPage

问题

I have a nested DataList in MasterPage. I'm trying to Findcontrol, but it returns null for DataList2.

What I tried so far :

DataList DataList1 = Page.Master.FindControl("DataListMain") as DataList;

DataList DataList2 = DataList1.FindControl("DataListNested") as DataList;

How can I fix this?

回答1:

DataList has items. So you need to locate the nested DataList by index.

DataList dl = ((DataList)Master.FindControl("DataListMain")).Items[i].FindControl("DataListNested") as DataList;

Note however that the contents of the Master Page are loaded AFTER the contents of the page using that master.

来源：https://stackoverflow.com/questions/51635185/findcontrol-returns-null-in-masterpage