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First commit on 4 Nov 2020
找不到文件
报错：[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: Invalid argument(s): Failed to load dynamic library (126)
找不到路径，最好先使用 resolve 转换一下字符串，这样报错的时候也知道从哪里开始算根目录。
import 'dart:io';
import 'dart:ffi';
final String dylibPath = Platform.script.resolve('./the-path/your-lib.dll').toFilePath();
final DynamicLibrary dylib = DynamicLibrary.open(dylibPath);
类型转换错误
报错：lib/main.dart(19,31): error G733AAF94: Expected type 'NativeFunction<Function(String)>' to be a valid and instantiated subtype of 'NativeType'. [*\flutter\flutter_assemble.vcxproj]
函数是先转成函数指针，再转成函数（下面两种方式）。另外传递字符串也要转成指针。
// `Utf8` 指针转换依赖 ffi 包
import 'package:ffi/ffi.dart';
// 方式 1
final funcPointer = dylib.lookup<NativeFunction<Function()>>('my_c_func');
final myDartFunc = funcPointer.asFunction<Function()>();
myDartFunc();
// 方式 2（带一个整型参数），`lookupFunction<>` 里
// 第一个对应 C 函数，整形用 Int32 声明，第二个对应 Dart 函数，用 int 声明。
final myDartFunc = dylib.lookupFunction<Function(Int32), Function(int)>('my_c_func');
myDartFunc(1);
// 字符串转换，如果用 Function(String) 则报错。
final myDartFunc = dylib.lookupFunction<Function(Pointer<Utf8>), Function(Pointer<Utf8>)>('my_c_func');
myDartFunc(Utf8.toUtf8('The argv string.'));
Porvider 和 setState() 错误
报错：flutter: Another exception was thrown: setState() or markNeedsBuild() called during build.
flutter: ══╡ EXCEPTION CAUGHT BY FOUNDATION LIBRARY ╞════════════════════════════════════════════════════════
flutter: The following assertion was thrown while dispatching notifications for YourModel:
flutter: setState() or markNeedsBuild() called during build.
flutter: This _InheritedProviderScope<YourModel> widget cannot be marked as needing to build because
flutter: the framework is already in the process of building widgets. A widget can be marked as needing to
flutter: be built during the build phase only if one of its ancestors is currently building. This exception
flutter: is allowed because the framework builds parent widgets before children, which means a dirty
flutter: descendant will always be built. Otherwise, the framework might not visit this widget during this
flutter: build phase.
flutter: The widget on which setState() or markNeedsBuild() was called was:
flutter: _InheritedProviderScope<YourModel>
flutter: The widget which was currently being built when the offending call was made was:
flutter: TextFormField
flutter:
flutter: When the exception was thrown, this was the stack:
flutter: #0 Element.markNeedsBuild.<anonymous closure> (package:flutter/src/widgets/framework.dart:4318:11)
flutter: #1 Element.markNeedsBuild (package:flutter/src/widgets/framework.dart:4333:6)
flutter: #2 _InheritedProviderScopeElement.markNeedsNotifyDependents (package:provider/src/inherited_provider.dart:491:5)
flutter: #3 ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:243:25)
flutter: #4 YourModel.title= (package:lifelog_client/module/directory/edit/model.dart:27:5)
flutter: #5 _FormTop.build.<anonymous closure>.<anonymous closure> (package:lifelog_client/module/directory/edit/form.dart:35:29)
flutter: #6 FormFieldState._validate (package:flutter/src/widgets/form.dart:468:37)
flutter: #7 FormFieldState.build (package:flutter/src/widgets/form.dart:518:13)
flutter: #8 StatefulElement.build (package:flutter/src/widgets/framework.dart:4792:27)
flutter: #9 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4675:15)
flutter: #10 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4847:11)
flutter: #11 Element.rebuild (package:flutter/src/widgets/framework.dart:4369:5)
flutter: #12 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:2777:33)
flutter: #13 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:894:21)
flutter: #14 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:320:5)
flutter: #15 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1117:15)
flutter: #16 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1055:9)
flutter: #17 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:971:5)
flutter: #21 _invoke (dart:ui/hooks.dart:157:10)
flutter: #22 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:252:5)
flutter: #23 _drawFrame (dart:ui/hooks.dart:120:31)
flutter: (elided 3 frames from dart:async)
flutter:
flutter: The YourModel sending notification was:
flutter: Instance of 'YourModel'
flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════
flutter: Another exception was thrown: setState() or markNeedsBuild() called during build.
这是在 Widget 重新 build() 完成之前调用了 setState()，在 Model 的 setter 里调用 notifyListeners() 的地方套个延迟就可以了：
Future.delayed(Duration(milliseconds: 500)).then((_) {
notifyListeners();
});
析构错误
[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: A YourModel was used after being disposed.
Once you have called dispose() on a YourModel, it can no longer be used.
#0 ChangeNotifier._debugAssertNotDisposed.<anonymous closure> (package:flutter/src/foundation/change_notifier.dart:117:9)
#1 ChangeNotifier._debugAssertNotDisposed (package:flutter/src/foundation/change_notifier.dart:123:6)
#2 ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:234:12)
#3 YourModel._notify.<anonymous closure> (package:lifelog_client/module/directory/edit/model.dart:14:7)
#4 _rootRunUnary (dart:async/zone.dart:1198:47)
#5 _CustomZone.runUnary (dart:async/zone.dart:1100:19)
#6 _FutureListener.handleValue (dart:async/future_impl.dart:143:18)
#7 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:696:45)
#8 Future._propagateToListeners (dart:async/future_impl.dart:725:32)
#9 Future._complete (dart:async/future_impl.dart:519:7)
#10 new Future.delayed.<anonymous closure> (dart:async/future.dart:323:16)
#11 _rootRun (dart:async/zone.dart:1182:47)
#12 _CustomZone.run (dart:async/zone.dart:1093:19)
#13 _CustomZone.runGuarded (dart:async/zone.dart:997:7)
#14 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1037:23)
#15 _rootRun (dart:async/zone.dart:1190:13)
#16 _CustomZone.run (dart:async/zone.dart:1093:19)
#17 _CustomZone.bindCallback.<anonymous closure> (dart:async/zone.dart:1021:23)
#18 Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
#19 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:397:19)
#20 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:428:5)
#21 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)
这是上一个执行延迟 notifyListeners() 的副作用，因为延时了，所以在 Widget 析构后调用了 setState()，解决办法是给 Model 自定义 dispose()，不执行通知。
未知错误
[ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: Unimplemented handling of missing static target
#0 _rootRunUnary (dart:async/zone.dart:1198:47)
#1 _CustomZone.runUnary (dart:async/zone.dart:1100:19)
#2 _FutureListener.handleValue (dart:async/future_impl.dart:143:18)
#3 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:696:45)
#4 Future._propagateToListeners (dart:async/future_impl.dart:725:32)
#5 Future._complete (dart:async/future_impl.dart:519:7)
#6 new Future.delayed.<anonymous closure> (dart:async/future.dart:323:16)
#7 _rootRun (dart:async/zone.dart:1182:47)
#8 _CustomZone.run (dart:async/zone.dart:1093:19)
#9 _CustomZone.runGuarded (dart:async/zone.dart:997:7)
#10 _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1037:23)
#11 _rootRun (dart:async/zone.dart:1190:13)
#12 _CustomZone.run (dart:async/zone.dart:1093:19)
#13 _CustomZone.bindCallback.<anonymous closure> (dart:async/zone.dart:1021:23)
#14 Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
#15 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:397:19)
#16 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:428:5)
#17 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)
重新 run 一下就好了，不知道是什么问题，等待复现。