BuildContext相比于Element，少了这些方法

BuildContext	Element
debugDoingBuild → bool	debugIsDefunct → bool
owner → BuildOwner?	depth → int
size → Size?	dirty → bool
widget → Widget	hashCode → int
	owner → BuildOwner?
	renderObject → RenderObject?
	size → Size?
	slot → Object?
	widget → Widget
dependOnInheritedElement(InheritedElement ancestor, {Object aspect}) → InheritedWidget	activate() → void
dependOnInheritedWidgetOfExactType({Object? aspect}) → T?	attachRenderObject(Object? newSlot) → void
describeElement(String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.errorProperty}) → DiagnosticsNode	deactivate() → void
describeMissingAncestor({required Type expectedAncestorType}) → List	deactivateChild(Element child) → void
describeOwnershipChain(String name) → DiagnosticsNode	debugDeactivated() → void
describeWidget(String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.errorProperty}) → DiagnosticsNode	debugDescribeChildren() → List
findAncestorRenderObjectOfType() → T?	debugFillProperties(DiagnosticPropertiesBuilder properties) → void
findAncestorStateOfType>() → T?	debugGetCreatorChain(int limit) → String
findAncestorWidgetOfExactType() → T?	debugGetDiagnosticChain() → List
findRenderObject() → RenderObject?	debugVisitOnstageChildren(ElementVisitor visitor) → void
findRootAncestorStateOfType>() → T?	dependOnInheritedElement(InheritedElement ancestor, {Object? aspect}) → InheritedWidget
getElementForInheritedWidgetOfExactType() → InheritedElement?	dependOnInheritedWidgetOfExactType({Object? aspect}) → T?
visitAncestorElements(bool visitor(Element element)) → void	describeElement(String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.errorProperty}) → DiagnosticsNode
visitChildElements(ElementVisitor visitor) → void	describeMissingAncestor({required Type expectedAncestorType}) → List
	describeOwnershipChain(String name) → DiagnosticsNode
	describeWidget(String name, {DiagnosticsTreeStyle style = DiagnosticsTreeStyle.errorProperty}) → DiagnosticsNode
	detachRenderObject() → void
	didChangeDependencies() → void
	findAncestorRenderObjectOfType() → T?
	findAncestorStateOfType>() → T?
	findAncestorWidgetOfExactType() → T?
	findRenderObject() → RenderObject?
	findRootAncestorStateOfType>() → T?
	forgetChild(Element child) → void
	getElementForInheritedWidgetOfExactType() → InheritedElement?
	inflateWidget(Widget newWidget, Object? newSlot) → Element
	markNeedsBuild() → void
	mount(Element? parent, Object? newSlot) → void
	performRebuild() → void
	reassemble() → void
	rebuild() → void
	toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
	toStringShort() → String
	unmount() → void
	update(covariant Widget newWidget) → void
	updateChild(Element? child, Widget? newWidget, Object? newSlot) → Element?
	updateSlotForChild(Element child, Object? newSlot) → void
	visitAncestorElements(bool visitor(Element element)) → void
	visitChildElements(ElementVisitor visitor) → void
	visitChildren(ElementVisitor visitor) → void
	operator ==(Object other) → bool
	describeElements(String name, Iterable elements) → DiagnosticsNode