registerForContextMenu有什么区别:Registersacontextmenutobeshownforthegivenview(multipleviewscanshowthecontextmenu).ThismethodwillsettheView.OnCreateContextMenuListenerontheviewtothisactivityCallregisterForContextMenu()andpassittheViewyouwanttogiveacontextmenu.WhenthisViewthenreceivesalong-press,itdis