Center（居中布局）在Center布局中，子元素处于水平和垂直方向的中间位置。代码如下：voidmain()=>runApp(MyApp());classMyAppextendsStatelessWidget{//Thiswidgetistherootofyourapplication.@overrideWidgetbuild(BuildContextcontext){returnMaterialApp(title:'Container布局',home:LayoutDemo(),);}}classLayoutDemoextendsStatelessWidget{@overrideWidge