dart “未处理的异常：调用onTap()时出现“NoSuchMethodError” |
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我是新的Flutter和最近开始工作，我的第一个Flutter项目。这个想法是当用户触摸按钮/图像时，它应该播放声音。我使用android studio来创建这个应用程序，我导入了一个名为Audioplayers的软件包来帮助播放音频。当我运行代码时，应用程序被构建并显示图像，但当我点击图像时，它给了我一个我无法解决的错误： Unhandled Exception: NoSuchMethodError: The getter 'position' was called on null这是密码： MaterialApp( home: Scaffold( backgroundColor: Colors.black, body: Center( child: GestureDetector( onTap: () { AudioPlayer audioPlayer = AudioPlayer(); audioPlayer.setVolume(1.0); playLocal() async { int result = await audioPlayer.play( 'path/to/mp3', isLocal: true); } }, child: Image( image: AssetImage('assetsproj/images/PngItem_4931119.png'), ), ), ), ), ),这是错误： E/flutter (11532): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: NoSuchMethodError: The getter 'position' was called on null. E/flutter (11532): Receiver: null E/flutter (11532): Tried calling: position E/flutter (11532): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:53:5) E/flutter (11532): #1 TapGestureRecognizer.handleTapDown (package:flutter/src/gestures/tap.dart:456:28) E/flutter (11532): #2 BaseTapGestureRecognizer._checkDown (package:flutter/src/gestures/tap.dart:256:5) E/flutter (11532): #3 BaseTapGestureRecognizer.didExceedDeadline (package:flutter/src/gestures/tap.dart:227:5) E/flutter (11532): #4 PrimaryPointerGestureRecognizer.didExceedDeadlineWithEvent (package:flutter/src/gestures/recognizer.dart:493:5) E/flutter (11532): #5 PrimaryPointerGestureRecognizer.addAllowedPointer. (package:flutter/src/gestures/recognizer.dart:446:40) E/flutter (11532): #6 _rootRun (dart:async/zone.dart:1122:38) E/flutter (11532): #7 _CustomZone.run (dart:async/zone.dart:1023:19) E/flutter (11532): #8 _CustomZone.runGuarded (dart:async/zone.dart:925:7) E/flutter (11532): #9 _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:965:23) E/flutter (11532): #10 _rootRun (dart:async/zone.dart:1126:13) E/flutter (11532): #11 _CustomZone.run (dart:async/zone.dart:1023:19) E/flutter (11532): #12 _CustomZone.bindCallback. (dart:async/zone.dart:949:23) E/flutter (11532): #13 Timer._createTimer. (dart:async-patch/timer_patch.dart:23:15) E/flutter (11532): #14 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:384:19) E/flutter (11532): #15 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:418:5) E/flutter (11532): #16 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:174:12) E/flutter (11532):我不知道为什么我得到这个错误。 |
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