“未经治疗的例外”，但我确实处理了！这是一个谜（对我来说）

Question

Fllutter＆Dart，当我尝试发送UDP数据包时，模拟器的屏幕被关闭时，发送失败。好的。 谜团是我无法以任何方式抓住失败。 UDP套接字Send（）不是异步，因此尝试＆捕获是正确的。如果我添加等待，什么都不会改变。如果我尝试附加.catcherror，则不允许使用它，因为它不是异步方法。

             try {
               print(_udpSocket.toString());  //It prints Instance of '_RawDatagramSocket'

               _udpSocket!.send(_packet,_serverAddress!,Server_UdpPort);  //Send packet
             } catch (exception) {
               print("aaaaaaaaaaaa");  //It never prints aaaaa, it never executes this code

               print(exception.toString());
             }

Console中的Error：

[ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: SocketException: Send failed (OS Error: Operation not permitted, errno = 1), address = 0.0.0.0, port = 0
E/flutter (25939): #0      _NativeSocket.send (dart:io-patch/socket_patch.dart:1213:34)
E/flutter (25939): #1      _RawDatagramSocket.send (dart:io-patch/socket_patch.dart:2460:15)
E/flutter (25939): #2      ClassServerConnection._handleOutcomingUdpStreamPacketsQueueEvent_async (package:meet2/2_1_4_ClassServerConnection.dart:1129:29)
E/flutter (25939): #3      ClassServerConnection._handleOutcomingUdpStreamPackets.<anonymous closure> (package:meet2/2_1_4_ClassServerConnection.dart:1090:93)
E/flutter (25939): #4      ClassQueue.callEvent.<anonymous closure> (package:meet2/2_1_2_ClassQueue.dart:78:68)
E/flutter (25939): #5      new Future.delayed.<anonymous closure> (dart:async/future.dart:424:39)
E/flutter (25939): #6      Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
E/flutter (25939): #7      _Timer._runTimers (dart:isolate-patch/timer_impl.dart:398:19)
E/flutter (25939): #8      _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:429:5)
E/flutter (25939): #9      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)

WLAN断开连接时，使用MDNS_DART存在完全相同的问题。我无法抓住例外。有消息吗？

Answer 1