I am trying to play a local video.the user choose video and play it on button press.The code Here.However I get this error and can't seem to get around it.
I/flutter ( 7097): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 7097): The following NoSuchMethodError was thrown building VideoChoosePost(dirty, state:
I/flutter ( 7097): _VideoChoosePostState#bd944):
I/flutter ( 7097): The getter 'value' was called on null
I/flutter ( 7097): Receiver: null
I/flutter ( 7097): Tried calling: value
You are not instantiating playercontroller any where in your code, so it has a value of null.
Related
I have the following Map from a JSON static file. I would like to add to the List that exists in the the Map already.
The below is an example of the Map.toString()
{'section': {'group1': {'name': 'bob', 'pets': ['dog', 'cat', 'hamster']}}}
I would like to add another pet to the existing pets list. I have attempted to use the below pattern based on a previous answer but it throws an error.
Map<String, dynamic> existingContent = json.decode(file.readAsStringSync());
List<dynamic> petList = existingContent['section']['group1']['pets'];
petList.add('peacock');
existingContent['section']['group1']['pets'] = petList.toList().toString();
E/flutter (20787): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)]
Unhandled Exception: NoSuchMethodError: The method '[]' was called on
null. E/flutter (20787): Receiver: null
Any help is greatly appreciated
Some method is initializing with null. There is no warnings or errors anywhere. And I triple checked the code that I thought had a mistake but I could not find anything.
Console Log Snippet:
I/flutter (21233): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY
╞═══════════════════════════════════════════════════════════
I/flutter (21233): The following NoSuchMethodError was thrown building Builder:
I/flutter (21233): The method '[]' was called on null.
I/flutter (21233): Receiver: null
I/flutter (21233): Tried calling:
I/flutter (21233): When the exception was thrown, this was the stack:
I/flutter (21233): #0
Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
I/flutter (21233): #1
ButtonsLists.foodList (package:customer/lists.dart:35:71)
I/flutter (21233): #2
ButtonsLists.foodList (package:customer/lists.dart:33:24)
=========================================================================
https://gist.github.com/Norman518/17be934d342b7523e80c7abc2e40aced
final List<MainButtons> buttonList = [
MainButtons(Icons.domain, 'Class Supplies', Page(suppliesList)),
MainButtons(Icons.local_dining, 'Food and Snacks', Page(foodList)),
MainButtons(Icons.hot_tub, 'Personal Supplies', Page(toiletriesList)),
MainButtons(Icons.local_cafe, 'Drinks', Page(drinksList))
];
MainButtons(this.image, this.name, this.onTap);
final IconData image;
final String name;
final Route onTap;
.
.
.
onTap: () {
Navigator.of(context).push(onTap);
},
=========================================================================
I expect four inkwell buttons to be displayed.
=========================================================================
Did the change, here is the console output
I/flutter ( 4037): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
I/flutter ( 4037): The following CyclicInitializationError was thrown building Builder:
I/flutter ( 4037): Reading static variable 'suppliesList' during its initialization
I/flutter ( 4037): When the exception was thrown, this was the stack:
I/flutter ( 4037): #0 ButtonsLists.suppliesList (package:customer/lists.dart:26:24)
I/flutter ( 4037): #1 new ButtonsLists (package:customer/lists.dart:55:54)
I/flutter ( 4037): #2 new BuyItem (package:customer/buyItem.dart:66:35)
I/flutter ( 4037): #3 ButtonsLists.buyItemList (package:customer/lists.dart:8:5)
I/flutter ( 4037): #4 ButtonsLists.buyItemList (package:customer/lists.dart:7:23)
I think the problem lies here
BrowsePage(this.buttonList);
final List<Widget> buttonList;
instead try this way
final List<Widget> buttonList;
BrowsePage(this.buttonList);
Don't put the list in the login page and buyitem, put it in the browsepage.
my json response is {"quoteText":"You\'re not obligated to win. You\'re obligated to keep trying to do the best you can every day.", "quoteAuthor":"Marian Edelman"} and I am trying to decode by Map<String, dynamic> quoteData = jsonDecode(response.body); but getting this exception
[ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter ( 5814): FormatException: Unrecognized string escape (at character 20)
E/flutter ( 5814): {"quoteText":"You\'re not obligated to win. You\'re obligated to keep tryin...
E/flutter ( 5814): ^
E/flutter ( 5814):
E/flutter ( 5814): #0 _ChunkedJsonParser.fail (dart:convert/runtime/libconvert_patch.dart:1358:5)
Tried by json.decode() and by doing flutter-remove-escape-sequence-in-dart but no luck. Any workaround?
That isn't valid json. Single quotes should not be escaped. Either you should get the source to fix it, or you can try to fix the string yourself by wholesale replacing any occurrence of \' with '.
String fixed = badString.replaceAll(r"\'", "'");
json.decode(fixed);
I use a Datepicker Cupertiono in my Flutter application:
https://github.com/wuzhendev/flutter-cupertino-date-picker
There is a method named "onConfirm()" where I'm trying to redirect user to other page, but with no luck.
I tried
return Navigator.pushReplacementNamed(ctx, '/otherPage');
but what actually happens when this return statment is hit, is cupertino widget closes and nothing happen. There is no error
When I try to use :
return Navigator.pushNamed<bool>(
ctx,
'/route/' + object.id.toString());
Some errors apear:
Performing hot restart...
Restarted application in 1 685ms.
I/flutter (20542): 112
E/flutter (20542): [ERROR:flutter/shell/common/shell.cc(188)] Dart Error: Unhandled exception:
E/flutter (20542): Looking up a deactivated widget's ancestor is unsafe.
E/flutter (20542): At this point the state of the widget's element tree is no longer stable. To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling
inheritFromWidgetOfExactType() in the widget's didChangeDependencies() method.
E/flutter (20542):
E/flutter (20542): #0 Element._debugCheckStateIsActiveForAncestorLookup.<anonymous closure> (package:flutter/src/widgets/framework.dart:3232:9)
E/flutter (20542): #1 Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:3241:6)
E/flutter (20542): #2 Element.ancestorStateOfType (package:flutter/src/widgets/framework.dart:3289:12)
E/flutter (20542): #3 Scaffold.of (package:flutter/src/material/scaffold.dart:935:42)
You should use Navigator.push.
Import your page, example: import './otherPage.dart';
Than change your line
return Navigator.pushReplacementNamed(ctx, '/otherPage');
To
return Navigator.push(context, 'otherClassName');
I've been trying to do something like the following inside a Polymer Dart 1.0 element
#PolymerRegister('some-element')
class SomeElement extends PolymerElement {
...
void fireEvent() {
fire('someevent');
}
...
}
I then listen for it in this manner
<some-element on-someevent="handleSomeEvent"></some-element>
with the method defined inside the Polymer Element that I'm using in defined thus
#reflectable
void handleSomeEvent([_, __]) {
...
}
The problem is I get an
Unhandled exception
which wasn't helpful, and it took me a while to figure out that the above was causing it. If I remove the
#reflectable
annotation from the event handler method, I get the following
method `registered` not defined
I was wondering if there is a special way to handle custom events in Polymer Dart 1.0?
I can handle it this way
on['someevent'].listen(handleSomeEvent);
which does work, it's just I don't see why I shouldn't be able to handle it both ways. I'm thinking I'll be submitting a bug report on this, but I thought I'd put it here and check to see if I've done this correctly, since what I did, apart from using
#reflectable
which is Polymer Dart 1.0 specific, is what they say you should do in Polymer JS whose documentation can be found here
UPDATE
I should clarify, this exception happened at load time, when the element was being registered. I'll put the full exception in later, when I have a bit more time.
The exception I'm getting is the following
Exception: Uncaught Error: Unhandled exception:
Reflecting on un-marked type 'JsObjectImpl'
#0 _InstanceMirrorImpl._InstanceMirrorImpl (package:reflectable/src/reflectable_transformer_based.dart:150:9)
#1 ReflectableImpl.reflect (package:reflectable/src/reflectable_transformer_based.dart:1216:16)
#2 _setupReflectableMethods.<anonymous closure>.<anonymous closure> (package:polymer/src/common/polymer_descriptor.dart:151:49)
#3 JsObject._callMethod (dart:js:678)
#4 JsObject.callMethod (dart:js:618)
#5 PolymerRegister.initialize (package:polymer/src/common/polymer_register.dart:19:13)
#6 loadInitializers.<anonymous closure>.<anonymous closure> (package:initialize/src/static_loader.dart:46:32)
#7 _runInitQueue (package:initialize/initialize.dart:35:24)
#8 _runInitQueue.<anonymous closure> (package:initialize/initialize.dart:38:26)
#9 _RootZone.runUnary (dart:async/zone.dart:1165)
#10 _Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:502)
#11 _Future._propagateToListeners (dart:async/future_impl.dart:585)
#12 _Future._completeWithValue (dart:async/future_impl.dart:376)
#13 _Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:430)
#14 _microtaskLoop (dart:async/schedule_microtask.dart:43)
#15 _microtaskLoopEntry (dart:async/schedule_microtask.dart:52)
#16 _ScheduleImmediateHelper._handleMutation (dart:html:42565)
Stack Trace:
#0 JsObject._callMethod (dart:js:678)
#1 JsObject.callMethod (dart:js:618)
#2 PolymerRegister.initialize (package:polymer/src/common/polymer_register.dart:19:13)
#3 loadInitializers.<anonymous closure>.<anonymous closure> (package:initialize/src/static_loader.dart:46:32)
#4 _runInitQueue (package:initialize/initialize.dart:35:24)
#5 _runInitQueue.<anonymous closure> (package:initialize/initialize.dart:38:26)
#6 _RootZone.runUnary (dart:async/zone.dart:1165)
#7 _Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:502)
#8 _Future._propagateToListeners (dart:async/future_impl.dart:585)
#9 _Future._completeWithValue (dart:async/future_impl.dart:376)
#10 _Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:430)
#11 _microtaskLoop (dart:async/schedule_microtask.dart:43)
#12 _microtaskLoopEntry (dart:async/schedule_microtask.dart:52)
#13 _ScheduleImmediateHelper._handleMutation (dart:html:42565)
Further Info
Next time I ask for help, I'll just use the exact code I'm using. The method I'm annotating with
#reflectable
is called registered.
#reflectable
void registered([_, __]) {
....
}
If I change the name of this method to something else like
#reflectable
void someOtherName([_, __]) {
...
}
The exception doesn't occur. Sorry about that, it didn't occur to me the name of the method might have something to do with it. Again sorry, but I still would like some explanation as to why the name of the annotated method matters in this case.
This is just fine.
#reflectable
void handleSomeEvent([_, __]) {
...
}
Can you provide the project in a GitHub repo that allows to reproduce the problem?
An additional method would be
#Listen('someevent')
void handleSomeEvent([_, __]) {
...
}
(You don't need to add anything to HTML for this method).