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...
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...
最后请求一个新的 frame,随后会绘制新的 frame:onBuildScheduled->ensureVisualUpdate->scheduleFrame() 。当新的 frame 到来时执行渲染管线 void drawFrame() { buildOwner!.buildScope(renderViewElement!); //重新构建widget树 pipelineOwner.flushLayout(); // 更新布局 pipelineOwner.flushCompositingBits(); //...
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...
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(); ...
/// 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. /// ...
void_handleBuildScheduled(){// If we're in the process of building dirty elements, then changes// should not trigger a new frame.assert((){if(debugBuildingDirtyElements){throwFlutterError('Build scheduled during frame.\n''While the widget tree was being built, laid out, and painted, ''a...
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...
Build构建是Widget最开始执行的步骤过程,我们要弄懂原理就要从Widget一开始怎么运行去洞察他,首先我们知道Widget的更新运行要经过5个步骤: voiddrawFrame(){buildOwner!.buildScope(renderViewElement!);// 1.重新构建widgetsuper.drawFrame();//下面几个是在super.drawFrame()执行的pipelineOwner.flushLayout();// 2...
buildOwner.onBuildScheduled = _handleBuildScheduled; ... } 看到真实调用的是WidgetBinding._handleBuildScheduled方法,我们继续完善刚才的调用过程: 所以这里就可以看到我们调用setState方法最终会触发界面新的一帧绘制。 当触发新的一帧时,我们又回到最初的WidgetBinding.drawFrame方法中,那么builderOwner.buildScope方法...