Server Dart：从Dart服务器上的HTTP POST请求接收文件，并在服务器上保存/打印其内容

我有一个服务器端代码，它接受POST请求中的文件，并将内容复制到新文件中。我基本上是在复制上面提到的例子

当我使用curl post向服务器发送文件时，出现以下错误：

curl -v -F myfile=@C:/aaa.txt -H "Content-Type: text/plain" http://localhost8081

未处理的异常：

打印（body.request）

我也提到了这篇文章：但对我的情况没有帮助

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有关此问题的任何帮助都将非常有用。

此问题已通过软件包升级得到解决。问题在于软件包版本冲突。如果有人再次偶然发现这个问题，我强烈建议检查软件包版本并执行pub升级

通过软件包升级解决了此问题。问题在于软件包版本冲突。如果有人再次偶然发现这个问题，我强烈建议检查软件包版本并执行pub升级

stacktrace应该指向引发此异常的确切源位置。你能提供这个信息吗。似乎不是你问题中代码的一部分。我找不到上传服务器的位置。dart:12:54。你能指出你问题中的代码行（12）吗？@GünterZöchbauer我更新了问题中的stacktrace。请看一看，谢谢。@GünterZöchbauer刚刚更新了问题，uploadServer.dart是服务器的文件名。此问题通过软件包升级得到解决。包版本存在一些问题。stacktrace应指向引发此异常的确切源位置。你能提供这个信息吗。似乎不是你问题中代码的一部分。我找不到上传服务器的位置。dart:12:54。你能指出你问题中的代码行（12）吗？@GünterZöchbauer我更新了问题中的stacktrace。请看一看，谢谢。@GünterZöchbauer刚刚更新了问题，uploadServer.dart是服务器的文件名。此问题通过软件包升级得到解决。软件包版本存在一些问题。

curl -v -F myfile=@C:/aaa.txt -H "Content-Type: text/plain" http://localhost8081

type 'String' is not a subtype of type 'int' of 'index'.
#0      _StringBase.[] (dart:core-patch/string_patch.dart:231)
#1      main.<anonymous closure>.<anonymous closure>.<anonymous closure>  (file:///C:/Dart%20Examples/dart-samples-master/dart-samples-master/html5/web/file/dndfiles/uploadServer.dart:10:54)
#2      _RootZone.runUnary (dart:async/zone.dart:1149)
#3      _Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:551)
#4      _Future._propagateToListeners (dart:async/future_impl.dart:637)
#5      _Future._complete (dart:async/future_impl.dart:414)
#6      Stream.fold.<anonymous closure> (dart:async/stream.dart:624)
#7      _RootZone.runGuarded (dart:async/zone.dart:1076)
#8      _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:390)
#9      _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:399)
#10     _BufferingStreamSubscription._close (dart:async/stream_impl.dart:290)
#11     _SinkTransformerStreamSubscription._close (dart:async/stream_transformers.dart:95)
#12     _EventSinkWrapper.close (dart:async/stream_transformers.dart:18)
#13     _StringAdapterSink.close (dart:convert/string_conversion.dart:267)
#14     _Utf8ConversionSink.close (dart:convert/string_conversion.dart:324)
#15     _ConverterStreamEventSink.close (dart:convert/chunked_conversion.dart:84)
#16     _SinkTransformerStreamSubscription._handleDone (dart:async/stream_transformers.dart:140)
#17     _RootZone.runGuarded (dart:async/zone.dart:1076)
#18     _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:390)
#19     _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:399)
#20     _BufferingStreamSubscription._close (dart:async/stream_impl.dart:290)
#21     _ForwardingStream._handleDone (dart:async/stream_pipe.dart:112)
#22     _ForwardingStreamSubscription._handleDone (dart:async/stream_pipe.dart:180)
#23     _RootZone.runGuarded (dart:async/zone.dart:1076)
#24     _BufferingStreamSubscription._sendDone.sendDone (dart:async/stream_impl.dart:390)
#25     _BufferingStreamSubscription._sendDone (dart:async/stream_impl.dart:399)
#26     _BufferingStreamSubscription._close (dart:async/stream_impl.dart:290)
#27     _StreamController&&_SyncStreamControllerDispatch._sendDone (dart:async/stream_controller.dart:752)
#28     _StreamController._closeUnchecked (dart:async/stream_controller.dart:605)
#29     _StreamController.close (dart:async/stream_controller.dart:598)
#30     _HttpParser._closeIncoming (dart:io/http_parser.dart:1046)
#31     _HttpParser._doParse (dart:io/http_parser.dart:784)
#32     _HttpParser._parse (dart:io/http_parser.dart:330)
#33     _HttpParser._onData (dart:io/http_parser.dart:819)
#34     _RootZone.runUnaryGuarded (dart:async/zone.dart:1087)
#35     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341)
#36     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:270)
#37     _StreamController&&_SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:744)
#38     _StreamController._add (dart:async/stream_controller.dart:616)
#39     _StreamController.add (dart:async/stream_controller.dart:562)
#40     _Socket._onData (dart:io-patch/socket_patch.dart:1646)
#41     _RootZone.runUnaryGuarded (dart:async/zone.dart:1087)
#42     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341)
#43     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:270)
#44     _StreamController&&_SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:744)
#45     _StreamController._add (dart:async/stream_controller.dart:616)
#46     _StreamController.add (dart:async/stream_controller.dart:562)
#47     _RawSocket._RawSocket.<anonymous closure> (dart:io-patch/socket_patch.dart:1215)
#48     _NativeSocket.issueReadEvent.issue (dart:io-patch/socket_patch.dart:749)
#49     _microtaskLoop (dart:async/schedule_microtask.dart:41)
#50     _startMicrotaskLoop (dart:async/schedule_microtask.dart:50)
#51     _runPendingImmediateCallback (dart:isolate-patch/isolate_patch.dart:96)
#52     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:149)

--------------------------1e7b12f3c4249867
Content-Disposition: form-data; name="myfile"; filename="test.txt"
Content-Type: text/plain

abcdef

--------------------------1e7b12f3c4249867--

Instance of '_HttpRequest'