颤振NoSuchMethodError:方法'toDate‘被调用为null
颤振NoSuchMethodError:方法'toDate‘被调用为null
提问于 2022-03-18 17:15:43
引发了一个异常：NoSuchMethodError: The method 'toDate' was called on null。
异常：
══╡ EXCEPTION CAUGHT BY FOUNDATION LIBRARY ╞════════════════════════════════════════════════════════
The following assertion was thrown while dispatching notifications for TextEditingController:
setState() called after dispose(): _CommentsState#74ccc(lifecycle state: defunct, not mounted)
This error happens if you call setState() on a State object for a widget that no longer appears in
the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error
can occur when code calls setState() from a timer or an animation callback.
The preferred solution is to cancel the timer or stop listening to the animation in the dispose()
callback. Another solution is to check the "mounted" property of this object before calling
setState() to ensure the object is still in the tree.
This error might indicate a memory leak if setState() is being called because another object is
retaining a reference to this State object after it has been removed from the tree. To avoid memory
leaks, consider breaking the reference to this object during dispose().
When the exception was thrown, this was the stack:
#0 State.setState.<anonymous closure> (package:flutter/src/widgets/framework.dart:1137:9)
#1 State.setState (package:flutter/src/widgets/framework.dart:1172:6)
#2 _CommentsState.initState.<anonymous closure> (package:anime_space_app/widgets/comments.dart:33:41)
#3 ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:308:24)
#4 ValueNotifier.value= (package:flutter/src/foundation/change_notifier.dart:412:5)
#5 TextEditingController.value= (package:flutter/src/widgets/editable_text.dart:154:11)
#6 EditableTextState._value= (package:flutter/src/widgets/editable_text.dart:2161:23)
#7 EditableTextState._formatAndSetValue (package:flutter/src/widgets/editable_text.dart:2540:5)
#8 EditableTextState.userUpdateTextEditingValue (package:flutter/src/widgets/editable_text.dart:2769:5)
#9 RenderEditable._setTextEditingValue (package:flutter/src/rendering/editable.dart:735:27)
#10 RenderEditable._setSelection (package:flutter/src/rendering/editable.dart:755:5)
#11 RenderEditable.selectPositionAt (package:flutter/src/rendering/editable.dart:1974:5)
#12 RenderEditable.selectPosition (package:flutter/src/rendering/editable.dart:1950:5)
#13 TextSelectionGestureDetectorBuilder.onSingleTapUp (package:flutter/src/widgets/text_selection.dart:1158:26)
#14 _TextFieldSelectionGestureDetectorBuilder.onSingleTapUp (package:flutter/src/material/text_field.dart:89:11)
#15 _TextSelectionGestureDetectorState._handleTapUp (package:flutter/src/widgets/text_selection.dart:1511:29)
#16 TapGestureRecognizer.handleTapUp.<anonymous closure> (package:flutter/src/gestures/tap.dart:611:57)
#17 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:198:24)
#18 TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:611:11)
#19 BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:298:5)
#20 BaseTapGestureRecognizer.acceptGesture (package:flutter/src/gestures/tap.dart:269:7)
#21 GestureArenaManager.sweep (package:flutter/src/gestures/arena.dart:157:27)
#22 GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:443:20)
#23 GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:419:22)
#24 RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:322:11)
#25 GestureBinding._handlePointerEventImmediately (package:flutter/src/gestures/binding.dart:374:7)
#26 GestureBinding.handlePointerEvent (package:flutter/src/gestures/binding.dart:338:5)
#27 GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:296:7)
#28 GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:279:7)
#32 _invoke1 (dart:ui/hooks.dart:170:10)
#33 PlatformDispatcher._dispatchPointerDataPacket (dart:ui/platform_dispatcher.dart:331:7)
#34 _dispatchPointerDataPacket (dart:ui/hooks.dart:94:31)
(elided 3 frames from dart:async)
The TextEditingController sending notification was:
TextEditingController#722ea(TextEditingValue(text: ┤├, selection: TextSelection.collapsed(offset:
0, affinity: TextAffinity.downstream, isDirectional: false), composing: TextRange(start: -1, end:
-1)))
════════════════════════════════════════════════════════════════════════════════════════════════════
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
V/InputMethodManager(21258): Starting input: tba=site.animslash.app ic=io.flutter.plugin.editing.InputConnectionAdaptor@6a46c51 mNaviBarColor -15130582 mIsGetNaviBarColorSuccess true , NavVisible : true , NavTrans : false
D/InputMethodManager(21258): startInputInner - Id : 0
I/InputMethodManager(21258): startInputInner - mService.startInputOrWindowGainedFocus
D/InputTransport(21258): Input channel constructed: fd=159
D/InputTransport(21258): Input channel destroyed: fd=187
D/InputMethodManager(21258): SSI - flag : 0 Pid : 21258 view : site.animslash.app
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
E/SpannableStringBuilder(21258): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
E/SpannableStringBuilder(21258): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
E/SpannableStringBuilder(21258): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
E/SpannableStringBuilder(21258): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
D/ViewRootImpl@d406a90[MainActivity](21258): MSG_RESIZED: frame=Rect(0, 0 - 1440, 2960) ci=Rect(0, 84 - 0, 1032) vi=Rect(0, 84 - 0, 1032) or=١
D/ViewRootImpl@d406a90[MainActivity](21258): Relayout returned: old=[0,0][1440,2960] new=[0,0][1440,2960] result=0x1
surface={valid=true 497100464128} changed=false
D/InputMethodManager(21258): SSI - flag : 0 Pid : 21258 view : site.animslash.app
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
Another exception was thrown: setState() called after dispose(): _CommentsState#74ccc(lifecycle state: defunct, not
mounted)
Another exception was thrown: setState() called after dispose(): _CommentsState#74ccc(lifecycle state: defunct, not
mounted)
D/InputMethodManager(21258): SSI - flag : 0 Pid : 21258 view : site.animslash.app
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
Another exception was thrown: setState() called after dispose(): _CommentsState#74ccc(lifecycle state: defunct, not
mounted)
D/InputMethodManager(21258): SSI - flag : 0 Pid : 21258 view : site.animslash.app
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
D/InputMethodManager(21258): SSI - flag : 0 Pid : 21258 view : site.animslash.app
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
Another exception was thrown: setState() called after dispose(): _CommentsState#74ccc(lifecycle state: defunct, not
mounted)
D/ViewRootImpl@d406a90[MainActivity](21258): ViewPostIme pointer 0
D/ViewRootImpl@d406a90[MainActivity](21258): ViewPostIme pointer 1
Another exception was thrown: NoSuchMethodError: The method 'toDate' was called on null.
Another exception was thrown: setState() called after dispose(): _CommentsState#74ccc(lifecycle state: defunct, not
mounted)
I/TextInputPlugin(21258): Composing region changed by the framework. Restarting the input method.
D/InputMethodManager(21258): prepareNavigationBarInfo() DecorView@456f89[MainActivity]
D/InputMethodManager(21258): getNavigationBarColor() -15130582
V/InputMethodManager(21258): Starting input: tba=site.animslash.app ic=io.flutter.plugin.editing.InputConnectionAdaptor@67a2caf mNaviBarColor -15130582 mIsGetNaviBarColorSuccess true , NavVisible : true , NavTrans : false
D/InputMethodManager(21258): startInputInner - Id : 0
I/InputMethodManager(21258): startInputInner - mService.startInputOrWindowGainedFocus
D/InputTransport(21258): Input channel constructed: fd=160
D/InputTransport(21258): Input channel destroyed: fd=159
W/IInputConnectionWrapper(21258): getExtractedText on inactive InputConnection
W/IInputConnectionWrapper(21258): getTextBeforeCursor on inactive InputConnection
E/SpannableStringBuilder(21258): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
I/chatty (21258): uid=10334(site.animslash.app) identical 2 lines
E/SpannableStringBuilder(21258): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
Another exception was thrown: NoSuchMethodError: The method 'toDate' was called on null.源代码：
class Comments extends StatefulWidget { Comments({this.title}); final String? title; @override State<Comments> createState() =>
_CommentsState(); }
class _CommentsState extends State<Comments> { @override void initState() {
getcurrentuser();
CommentController.addListener(() => setState(() {}));
super.initState(); }
void getcurrentuser() {
try {
final user = _auth.currentUser;
if (user != null) {
signinUser = user;
print(signinUser.email);
}
} catch (e) {
print(e);
} }
@override Widget build(BuildContext context) {
final CmID = FirebaseFirestore.instance
.collection('Comments')
.doc('${widget.title}')
.collection('Comments')
.doc()
.id;
return Scaffold(
backgroundColor: kPrimaryColor,
body: SafeArea(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
decoration: BoxDecoration(
color: kBackgroundColor,
border: Border(
top: BorderSide(
color: kBackgroundColor,
width: 2,
),
),
),
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Expanded(
child: TextFormField(
controller: CommentController,
validator: (val) {
if (val!.isEmpty || val.length <= 2) {
return "الرجاء ادخال تعليق صحيح";
} else {
return null;
}
},
style: TextStyle(color: Colors.white),
decoration: InputDecoration(
prefixIcon: Icon(Icons.comment, color: Colors.white),
labelText: 'ادخل تعليقك',
labelStyle: TextStyle(color: Colors.white),
prefixStyle: TextStyle(color: Colors.white),
iconColor: Colors.blue,
contentPadding: EdgeInsets.symmetric(
vertical: 10,
horizontal: 20,
),
prefixIconColor: Colors.blue,
suffixIcon: CommentController.text.isEmpty
? Container(
width: 0,
)
: IconButton(
splashRadius: 22,
onPressed: () => CommentController.clear(),
icon: Icon(Icons.close),
),
border: OutlineInputBorder(
borderSide: BorderSide(color: Colors.blue),
),
disabledBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.blue),
),
enabledBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.white),
),
focusColor: Colors.blue,
hoverColor: Colors.blue,
),
),
),
SizedBox(width: 10),
TextButton(
style: ButtonStyle(),
onPressed: () async {
if (CommentController.text.isEmpty ||
CommentController.text.length < 3) {
Fluttertoast.showToast(
msg: 'يجب على تعليقك ان يكون حرفين او اكثر',
backgroundColor: kBackgroundColor,
);
} else {
final commentid = FirebaseFirestore.instance
.collection('Comments')
.doc(widget.title)
.collection('Comments')
.doc();
final json = {
'id': commentid.id,
'sender': signinUser.displayName,
'img': signinUser.photoURL,
'time': FieldValue.serverTimestamp(),
'text': CommentController.text,
};
await commentid.set(json);
CommentController.clear();
}
},
child: Text(
'ارسال',
style: TextStyle(
color: Colors.blue,
fontWeight: FontWeight.bold,
fontSize: 14,
),
),
),
],
),
),
),
),
CommentsStreamBuilder(
title: '${widget.title}',
),
],
)),
); } }
class CommentsLine extends StatelessWidget {
CommentsLine(
{required this.time,
this.title,
this.img,
this.text,
this.sender,
required this.isMe});
final String? title;
final Timestamp time;
final String? sender;
final String? text;
final bool isMe;
final String? img;
@override
Widget build(BuildContext context) {
DateTime minAgo = DateTime.now().subtract(const Duration(minutes: 1));
DateTime secAgo = DateTime.now().subtract(const Duration(seconds: 1));
DateTime dayAgo = DateTime.now().subtract(const Duration(days: 1));
DateTime monAgo = DateTime.now().subtract(const Duration(days: 30));
return Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(8), color: kBackgroundColor),
width: MediaQuery.of(context).size.width,
margin: EdgeInsets.symmetric(vertical: 8),
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: [
Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: [
Text(
'$sender',
style: TextStyle(color: Colors.white, fontSize: 14),
),
SizedBox(
height: 5,
),
Text(
timeago.format(time.toDate(), locale: 'ar'),
style: TextStyle(color: Colors.white70, fontSize: 12),
)
],
),
SizedBox(
width: 10,
),
CircleAvatar(
radius: 20,
backgroundImage: NetworkImage('$img'),
),
],
),
SizedBox(
height: 8,
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
'$text',
style: TextStyle(color: Colors.white, fontSize: 16),
),
),
],
),
),
);
}
}
class CommentsStreamBuilder extends StatelessWidget {
CommentsStreamBuilder({this.title});
final String? title;
@override
Widget build(BuildContext context) {
return StreamBuilder<QuerySnapshot>(
stream: _firestore
.collection('Comments')
.doc('$title')
.collection('Comments')
.orderBy('time')
.snapshots(),
builder: (context, snapshot) {
List<CommentsLine> commentsWidget = [];
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(
backgroundColor: kBackgroundColor,
),
);
}
if (snapshot.data?.docs.isEmpty != false) {
return Center(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.center,
children: [
Image.asset(
'images/cry.gif',
height: 110,
),
SizedBox(
height: 20,
),
Text(
"لاتوجد تعليقات",
style: TextStyle(color: Colors.white),
),
],
),
);
}
final messages = snapshot.data!.docs.reversed;
for (var message in messages) {
final messagetext = message.get('text');
final messgaesender = message.get('sender');
final messgaeimg = message.get('img');
final datatime = message.get('time');
final currentUser = signinUser.displayName;
final commentWidget = CommentsLine(
sender: messgaesender,
time: datatime,
img: messgaeimg,
text: messagetext,
isMe: currentUser == messgaesender,
title: title,
);
commentsWidget.add(commentWidget);
}
return Expanded(
child: ListView(
reverse: false,
padding: EdgeInsets.symmetric(horizontal: 10, vertical: 20),
children: commentsWidget,
),
);
},
);
}
}Stack Overflow用户
发布于 2022-03-18 20:48:31
所以问题可能是你不清楚你的资源是否正确。在initState方法中，您有如下内容：
@override
void initState() {
getcurrentuser();
CommentController.addListener(() => setState(() {})); // This causes the issue
super.initState();
}问题是，即使在卸载addListener之后也会执行_CommentsState回调。也就是说，当您添加侦听器时，稍后也应该删除它。
你可以这样做：
class _CommentsState extends State<Comments> {
@override
void initState() {
super.initState(); // Notice I moved this up as well
getcurrentuser();
CommentController.addListener(_updateState); // Add listener on init
}
@override
void dispose() {
CommentController.removeListener(_updateState); // Remove listener on dispose
super.dispose();
}
void _updateState() => setState(() {});
@override
Widget build(BuildContext context) {
...
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/71530819
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