在构建期间调用 setState() 或 markNeedsBuild()。该覆盖小部件无法标记为需要构建

我尝试在 {AbsorbPointer} （特别是 {GestureDetector} onPanEnd）调用的 'fling' 函数的 SetState() 内使用 'showGeneralDialog' 编写动画对话框脚本。我附加了简单的代码，我尝试用未来的异步等待等来完成它，但可能我不明白。

'child: EasyDialog' 在我的代码中定义为 void 函数。 这是我的调试控制台和附加的代码

如果有人能指导我如何在 setState 期间完成动画（pageBuilder），我会很高兴。

[38;5;248m════════ Exception caught by widgets library ═══════════════════════════════════[39;49m
[38;5;244mThe following assertion was thrown building Builder(dirty, dependencies: [_LocalizationsScope-[GlobalKey#3e9b6]]):[39;49m
setState() or markNeedsBuild() called during build.

[38;5;244mThis Overlay widget cannot be marked as needing to build because the framework is already in the process of building widgets.  A widget can be marked as needing to be built during the build phase only if one of its ancestors is currently building. This exception is allowed because the framework builds parent widgets before children, which means a dirty descendant will always be built. Otherwise, the framework might not visit this widget during this build phase.[39;49m
[38;5;244mThe widget on which setState() or markNeedsBuild() was called was: Overlay-[LabeledGlobalKey<OverlayState>#2acd6][39;49m
    [38;5;244mstate: OverlayState#6a2d6(entries: [OverlayEntry#9eb98(opaque: true; maintainState: false), OverlayEntry#7538d(opaque: false; maintainState: true), OverlayEntry#dfb68(opaque: true; maintainState: false), OverlayEntry#12c39(opaque: false; maintainState: true), OverlayEntry#3ef90(opaque: true; maintainState: false), OverlayEntry#53522(opaque: false; maintainState: true), OverlayEntry#07377(opaque: false; maintainState: false), OverlayEntry#e5cbf(opaque: false; maintainState: true), OverlayEntry#f3375(opaque: false; maintainState: false), OverlayEntry#b6bdc(opaque: false; maintainState: true), OverlayEntry#34ca0(opaque: false; maintainState: false)])[39;49m
[38;5;244mThe widget which was currently being built when the offending call was made was: Builder[39;49m
    [38;5;244mdirty[39;49m
    [38;5;244mdependencies: [_LocalizationsScope-[GlobalKey#3e9b6]][39;49m
[38;5;244mThe relevant error-causing widget was[39;49m
[38;5;248mSlideTransition[39;49m
 lib\main.dart
[38;5;244mWhen the exception was thrown, this was the stack[39;49m
[38;5;244m#0      Element.markNeedsBuild.<anonymous closure>[39;49m
 package:flutter/…/widgets/framework.dart
[38;5;244m#1      Element.markNeedsBuild[39;49m
 package:flutter/…/widgets/framework.dart
[38;5;244m#2      State.setState[39;49m
 package:flutter/…/widgets/framework.dart
[38;5;244m#3      OverlayState.rearrange[39;49m
 package:flutter/…/widgets/overlay.dart
[38;5;244m#4      NavigatorState._flushHistoryUpdates[39;49m
 package:flutter/…/widgets/navigator.dart
[38;5;244m...[39;49m
[38;5;248m════════════════════════════════════════════════════════════════════════════════[39;49m
E/flutter (30352): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: 'package:flutter/src/widgets/navigator.dart': Failed assertion: line 2976 pos 18: '!navigator._debugLocked': is not true.
[38;5;244mE/flutter (30352): #0      _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:46:39)[39;49m
[38;5;244mE/flutter (30352): #1      _AssertionError._throwNew (dart:core-patch/errors_patch.dart:36:5)[39;49m
[38;5;244mE/flutter (30352): #2      _RouteEntry.handlePush.<anonymous closure>[39;49m
 package:flutter/…/widgets/navigator.dart
[38;5;244mE/flutter (30352): #3      TickerFuture.whenCompleteOrCancel.thunk[39;49m
 package:flutter/…/scheduler/ticker.dart
[38;5;244mE/flutter (30352): #4      _rootRunUnary (dart:async/zone.dart:1194:47)[39;49m
[38;5;244mE/flutter (30352): #5      _CustomZone.runUnary (dart:async/zone.dart:1097:19)[39;49m
[38;5;244mE/flutter (30352): #6      _FutureListener.handleValue (dart:async/future_impl.dart:150:18)[39;49m
[38;5;244mE/flutter (30352): #7      Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:703:45)[39;49m
[38;5;244mE/flutter (30352): #8      Future._propagateToListeners (dart:async/future_impl.dart:732:32)[39;49m
[38;5;244mE/flutter (30352): #9      Future._completeWithValue (dart:async/future_impl.dart:536:5)[39;49m
[38;5;244mE/flutter (30352): #10     Future._asyncCompleteWithValue.<anonymous closure> (dart:async/future_impl.dart:574:7)[39;49m
[38;5;244mE/flutter (30352): #11     _rootRun (dart:async/zone.dart:1186:13)[39;49m
[38;5;244mE/flutter (30352): #12     _CustomZone.run (dart:async/zone.dart:1090:19)[39;49m
[38;5;244mE/flutter (30352): #13     _CustomZone.runGuarded (dart:async/zone.dart:994:7)[39;49m
[38;5;244mE/flutter (30352): #14     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1034:23)[39;49m
[38;5;244mE/flutter (30352): #15     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)[39;49m
[38;5;244mE/flutter (30352): #16     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)[39;49m
E/flutter (30352):
E/flutter (30352): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: 'package:flutter/src/widgets/navigator.dart': Failed assertion: line 2976 pos 18: '!navigator._debugLocked': is not true.
[38;5;244mE/flutter (30352): #0      _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:46:39)[39;49m
[38;5;244mE/flutter (30352): #1      _AssertionError._throwNew (dart:core-patch/errors_patch.dart:36:5)[39;49m
[38;5;244mE/flutter (30352): #2      _RouteEntry.handlePush.<anonymous closure>[39;49m
 package:flutter/…/widgets/navigator.dart
[38;5;244mE/flutter (30352): #3      TickerFuture.whenCompleteOrCancel.thunk[39;49m
 package:flutter/…/scheduler/ticker.dart
[38;5;244mE/flutter (30352): #4      _rootRunUnary (dart:async/zone.dart:1194:47)[39;49m
[38;5;244mE/flutter (30352): #5      _CustomZone.runUnary (dart:async/zone.dart:1097:19)[39;49m
[38;5;244mE/flutter (30352): #6      _FutureListener.handleValue (dart:async/future_impl.dart:150:18)[39;49m
[38;5;244mE/flutter (30352): #7      Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:703:45)[39;49m
[38;5;244mE/flutter (30352): #8      Future._propagateToListeners (dart:async/future_impl.dart:732:32)[39;49m
[38;5;244mE/flutter (30352): #9      Future._completeWithValue (dart:async/future_impl.dart:536:5)[39;49m
[38;5;244mE/flutter (30352): #10     Future._asyncCompleteWithValue.<anonymous closure> (dart:async/future_impl.dart:574:7)[39;49m
[38;5;244mE/flutter (30352): #11     _rootRun (dart:async/zone.dart:1186:13)[39;49m
[38;5;244mE/flutter (30352): #12     _CustomZone.run (dart:async/zone.dart:1090:19)[39;49m
[38;5;244mE/flutter (30352): #13     _CustomZone.runGuarded (dart:async/zone.dart:994:7)[39;49m
[38;5;244mE/flutter (30352): #14     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1034:23)[39;49m
[38;5;244mE/flutter (30352): #15     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)[39;49m
[38;5;244mE/flutter (30352): #16     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)[39;49m
E/flutter (30352):
I/ViewRootImpl@738e9ee[MainActivity](30352): ViewPostIme pointer 0

  fling(details) {
    final simulation = FrictionSimulation(/**/

    );
    _spinController.animateWith(simulation).then((_) => setState(() {
          absorbing = false;
          Timer(Duration(milliseconds: 500), () {
            showGeneralDialog(
              barrierLabel: "Label",
              barrierDismissible: true,
              barrierColor: Colors.black.withOpacity(0.5),
              transitionDuration: Duration(milliseconds: 700),
              context: context,
              pageBuilder: (context, anim1, anim2) {
                return Align(
                  alignment:
                      _fromTop ? Alignment.topCenter : Alignment.bottomCenter,
                  child: Container(
                    height: 300,
                    child: SizedBox.expand(
                        child: EasyDialog(
                      closeButton: true,
                      cardColor: Colors.white.withOpacity(0.3),
                      contentPadding: const EdgeInsets.only(bottom: 100),
                      title: Text(
                        "Task Dialog",
                        textScaleFactor: 1.2,
                      ),
                      description: Text(
                        text[Random().nextInt(text.length)],
                      ),
                      topImage: AssetImage('assets/images/cbg82.jpg'),
                      height: 400,
                      width: 350,
                    ).show(context)),
                    margin: EdgeInsets.only(
                        top: 50, left: 12, right: 12, bottom: 50),
                    decoration: BoxDecoration(
                      color: Colors.white,
                      borderRadius: BorderRadius.circular(40),
                    ),
                  ),
                );
              },
              transitionBuilder: (context, anim1, anim2, child) {
                return SlideTransition(
                  position: Tween(
                          begin: Offset(0, _fromTop ? -1 : 1),
                          end: Offset(0, 0))
                      .animate(anim1),
                  child: child,
                );
              },
            );
          });
        }));
    setState(() => absorbing = true);
  }
///

  @override
  Widget build(BuildContext context) {
    return Scaffold(
    /*appbars*/
      body: Container(
          child: Column(
            children: <Widget>[
              Card(
                  child: AbsorbPointer(
                    absorbing: absorbing,
                    child: GestureDetector(
                      behavior: HitTestBehavior.translucent,
                      onPanUpdate: (d) =>
                          _spinController.value += d.delta.dx / 100,
                      onPanEnd: fling,
                      child: SizedBox(
                        child: RotationTransition(
                            turns: _spinController,
                            child: FittedBox(
                                alignment: Alignment.center,
                                fit: BoxFit.fill,
                                child: Image.asset(
                                  _imageToShow,
                                  height: _aHeight,
                                  width: _aWidth,
                                ))),
                      ),
                    ),
                  )),
            ],
          )),
    );
  }

谢谢 ：）

您收到此错误是因为您在页面构建完成之前正在执行某些操作。所以你必须等待。

怎么样使用addPostFrameCallback?

从以下位置查看此信息官方颤振文档 https://api.flutter.dev/flutter/scheduler/SchedulerBinding/addPostFrameCallback.html.

安排此帧结束时的回调。

不请求新框架。

此回调在持久帧之后的帧期间运行 回调（这是当主渲染管道已经 酡）。如果帧正在进行中并且帧后回调尚未进行 尚未执行，那么注册的回调仍然执行 帧期间。否则，执行注册的回调 在下一帧期间。

回调按照添加的顺序执行。

帧后回调无法取消注册。他们被准确地称为 一次。

所以你可以这样做：

  SchedulerBinding.instance.addPostFrameCallback((_) {
    //yourcode
  });

另一个原因可能是（如果不看到整个代码就很难判断）您正在执行一个onPressed or onTap在构建阶段立即回调。确保你没有类似的东西onTap: onTap()在你的代码中。相反你需要做onTap: onTap.