在flutter中进行几次调试后显示错误，“类型'Null'不是类型转换中'int'类型的子类型”

Question

[Unhandled exception:
type 'Null' is not a subtype of type 'int' in type cast
#0      Session._refreshSessionData.parseContents (package:unified_analytics/src/session.dart:85:43)
#1      Session._refreshSessionData (package:unified_analytics/src/session.dart:89:7)
#2      new Session (package:unified_analytics/src/session.dart:28:5)
#3      new AnalyticsImpl (package:unified_analytics/src/analytics.dart:427:23)
#4      new Analytics (package:unified_analytics/src/analytics.dart:83:12)
#5      getAnalytics (package:flutter_tools/src/reporting/unified_analytics.dart:51:10)
#6      runInContext.<anonymous closure> (package:flutter_tools/src/context_runner.dart:92:24)
#7      AppContext._generateIfNecessary.<anonymous closure> (package:flutter_tools/src/base/context.dart:107:42)
#8      _LinkedHashMapMixin.putIfAbsent (dart:collection-patch/compact_hash.dart:543:23)
#9      AppContext._generateIfNecessary (package:flutter_tools/src/base/context.dart:95:20)
#10     AppContext.get (package:flutter_tools/src/base/context.dart:124:32)
#11     analytics (package:flutter_tools/src/globals.dart:96:36)
#12     _handleToolError (package:flutter_tools/runner.dart:190:13)
#13     run.<anonymous closure>.<anonymous closure> (package:flutter_tools/runner.dart:142:13)
#14     _rootRunBinary (dart:async/zone.dart:1423:47)
#15     _CustomZone.runBinary (dart:async/zone.dart:1315:19)
#16     runZonedGuarded.<anonymous closure> (dart:async/zone.dart:1776:18)
#17     _Zone._processUncaughtError (dart:async/zone.dart:1081:14)
#18     _CustomZone.handleUncaughtError (dart:async/zone.dart:1285:5)
#19     Future._propagateToListeners (dart:async/future_impl.dart:788:16)
#20     Future._completeError (dart:async/future_impl.dart:651:5)
#21     Future._asyncCompleteError.<anonymous closure> (dart:async/future_impl.dart:737:7)
#22     _rootRun (dart:async/zone.dart:1399:13)
#23     _CustomZone.run (dart:async/zone.dart:1301:19)
#24     _CustomZone.runGuarded (dart:async/zone.dart:1209:7)
#25     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1249:23)
#26     _microtaskLoop (dart:async/schedule_microtask.dart:40:21)
#27     _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)
#28     _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:118:13)
#29     _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:185:5)]

当我最初调试我的项目时，没有错误。然而调试了几次之后，突然出现了错误。尽管重新启动 Visual Studio 并尝试创建新项目，但同样的错误仍然存在。此外，重新安装 Flutter 和 Dart 并没有解决问题。

请帮忙。谢谢你

Answer 1

在session.dart文件中，参见第85行。这主要是由于将一个为null或可能为null的值传递给int类型1。所以看看这个值是否可以为空，或者如果你没有给它一个值或者它可以为空