PopupMenuButton
JustcreatethepopupmenuregisteringtheviewthepopupwillshowunderneathandusethegetMenu()methodtoaddthevalues.,Iwanttodisplayaloginmenuitemiftheuserisloggedoutandalogoutbuttoniftheuserisloggedin.HowcanIdothisdynamically?,Thisdocumentshowshowtocreateth...。參考影片的文章的如下: