One time while doing the project, I was in panic when the view dropdown button is missing in the list view or allitems.aspx. One thing I remember is that I edit the page in Site Actions menu then I accidentally click the “x” mark. Clicking the “x” mark will close the webpart. After that I just add the list webpart to show it again and poof! The view dropdown is missing.
Now I will show you how to restore the view dropdown…