之所以叫persistentCallbacks是因为每帧都会执行,执行完后不会删除persistentCallbacks列表。 其中最引人注目的是此方法RendererBinding.drawFrame,其过程如下: For more details, see PipelineOwner. The build phase: 这个阶段是WidgetsBinding的drawFrame中的。WidgetsBinding 继承了SchedulerBinding。 if (renderViewElement !
它包含的最主要的几个类有: class WidgetsFlutterBinding extends BindingBase with GestureBinding, ServicesBinding, SchedulerBinding, PaintingBinding, RendererBinding, WidgetsBinding { ... } abstract class Widget extends DiagnosticableTree { ... } abstract class StatelessWidget extends Widget { ... } abstract...
class WidgetsFlutterBinding extends BindingBase with GestureBinding, ServicesBinding, SchedulerBinding, PaintingBinding, RendererBinding, WidgetsBinding { ... }abstract class Widget extends DiagnosticableTree { ... } abstract class StatelessWidget extends Widget { ... } abstract class StatefulWidget extends Wi...
它包含的最主要的几个类有: class WidgetsFlutterBinding extends BindingBase with GestureBinding, ServicesBinding, SchedulerBinding, PaintingBinding, RendererBinding, WidgetsBinding { ... } abstract class Widget extends DiagnosticableTree { ... } abstract class StatelessWidget extends Widget { ... } abstract...
classWidgetsFlutterBindingextendsBindingBasewithGestureBinding,ServicesBinding,SchedulerBinding,PaintingBinding,RendererBinding,WidgetsBinding{ ... }abstractclassWidgetextendsDiagnosticableTree{ ... }abstractclassStatelessWidgetextendsWidget{ ... }abstractclassStatefulWidgetextendsWidget{ ... }abstractclassRenderObjectWidget...
收到刷新事件后,先调用 WidgetsBinding.drawFame 方法。这个方法重建 Widget 树,这一过程上篇文章有详细介绍,这里不多做赘述。 //WidgetsBindingvoiddrawFrame(){...if(renderViewElement!=null)buildOwner.buildScope(renderViewElement);super.drawFrame();...} ...
内容回顾:onBuildScheduled方法是在WidgetsBinding的initInstances中初始化的,一系列调用后最后调用的就是scheduleFrame请求Native Platform要刷新界面。 将element加入到dirtyElements中。 在合适的时候Flutter Engine会回调SchedulerBinding的handleDrawFrame方法,最后会调用BuildOwner的buildScope方法。
Flutter控件主要分为两大类,StatelessWidget和StatefulWidget,StatelessWidget用来展示静态的文本或者图片,如果控件需要根据外部数据或者用户操作来改变的话,就需要使用StatefulWidget。State的概念也是来源于Facebook的流行Web框架React,React风格的框架中使用控件树和各自的状态来构建界面,当某个控件的状态发生变化时由框架负责对比...
classWidgetsFlutterBindingextendsBindingBasewithGestureBinding,ServicesBinding,SchedulerBinding, PaintingBinding,RendererBinding,WidgetsBinding{ ... } abstractclassWidgetextendsDiagnosticableTree{ ... } abstractclassStatelessWidgetextendsWidget{ ... } abstractclassStatefulWidgetextendsWidget{ ... } ...
classWidgetsFlutterBindingextendsBindingBasewithGestureBinding,ServicesBinding,SchedulerBinding,PaintingBinding,RendererBinding,WidgetsBinding{...}abstractclassWidgetextendsDiagnosticableTree{...}abstractclassStatelessWidgetextendsWidget{...}abstractclassStatefulWidgetextendsWidget{...}abstractclassRenderObjectWidgetextendsWidget...