.buildScope(renderViewElement!);// 1.重新构建widgetsuper.drawFrame();//下面几个是在super.drawFrame()执行的pipelineOwner.flushLayout();// 2.更新布局pipelineOwner.flushCompositingBits();//3.更新“层合成”信息pipelineOwner.flushPaint();// 4.重绘if(sendFramesToEngine){renderView.compositeFrame();...
buildOwner.onBuildScheduled =_handleBuildScheduled;} 回到上边onBuildScheduled()的调用,会调用到ensureVisualUpdate() void_handleBuildScheduled() {ensureVisualUpdate();}voidensureVisualUpdate() {switch(schedulerPhase) {caseSchedulerPhase.idle:caseSchedulerPhase.postFrameCallbacks:scheduleFrame();return;caseSch...
postFrameCallbacks:在Frame结束时只会被调用一次,调用后会被系统移除,可由 SchedulerBinding.instance.addPostFrameCallback() 注册,注意,不要在此类回调中再触发新的Frame,这可以会导致循环刷新。 handleBeginFrame() 和 handleDrawFrame() 两个方法的源码,可以发现前者主要是执行了transientCallbacks队列,而后者执行了...
First, this is sort of a second step in another issue I had, which can be further explained byhttps://stackoverflow.com/questions/72006417/build-scheduled-during-frame-after-changing-tab-in-tab-bar?noredirect=1#comment127252356_72006417. Without asking you to go and check that question for t...
/// 2. Microtasks: After [handleBeginFrame] returns, any microtasks that got /// scheduled by transient frame callbacks get to run. This typically includes /// callbacks for futures from [Ticker]s and [AnimationController]s that /// completed this frame. ...
void_handleBuildScheduled(){// If we're in the process of building dirty elements, then changes// should not trigger a new frame.assert((){if(debugBuildingDirtyElements){throwFlutterError.fromParts(<DiagnosticsNode>[ErrorSummary('Build scheduled during frame.'),ErrorDescription('While the widget...
/// This is used during application startup so that the first frame (which is /// likely to be quite expensive) gets a few extra milliseconds to run. /// /// Locks events dispatching until the scheduled frame has completed. /// ...
我们从BottomSheet的源码看,内部其实是通过获取用户的滑动距离配合AnimationBuilder实现的动态改变弹框高度,从而实现的上拉下拉的动画效果。 image.png 而当包含Listview时,由于Listview的本身滑动机制使得BottomSheet内部的触摸事件无法传递所致,所以从这里入手我们直接自己来处理整个用户的触摸手势,当listview在顶部时手势响应下...
Steps to Reproduce Run example code below Drag the listview to the bottom letting it overscroll. After a few attempt it should freezes and throw a " build scheduled during frame" error Expected results: Should not freeze or throw an erro...
void _handleBuildScheduled() { ensureVisualUpdate(); } 1. 2. 3. ensureVisualUpdate 方法定义在SchedulerBinding类中: void ensureVisualUpdate() { switch (schedulerPhase) { case SchedulerPhase.idle: case SchedulerPhase.postFrameCallbacks: scheduleFrame(); ...