当我从size函数内部调用Greet时,DisplayAlert会按预期显示警报但是,当在事件发生后从委托(delegate)中调用它时,它将使用正确的名称(GreetHasbeenCalled)记录到输出,但DisplayAlert不会节目。publicclassCustomPage:ContentPage{...protectedoverridevoidOnValidSizeAllocated(doublewidth,doubleheight){...Greet("Test");app.FB.GetName();app.FB.NameRecieved+=(s,e)=>{Greet(