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Questions tagged [statefulwidget]

339 questions
342
votes
8 answers

Passing data to StatefulWidget and accessing it in its state in Flutter

I have 2 screens in my Flutter app: a list of records and a screen for creating and editing records. If I pass an object to the second screen that means I am going to edit this and if I pass null it means that I am creating a new item. The editing…
moonvader
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8 answers

Passing Data to a Stateful Widget in Flutter

I'm wondering what the recommended way of passing data to a stateful widget, while creating it, is. The two styles I've seen are: class ServerInfo extends StatefulWidget { Server _server; ServerInfo(Server server) { this._server = server; …
Mojachiee
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155
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12 answers

What is the relation between stateful and stateless widgets in Flutter?

A stateful widget is defined as any widget which changes its state within its lifetime. But it is a very common practice for a StatelessWidget to have a StatefulWidget as one of its children. Doesn't StatelessWidget become stateful if it has…
user462455
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5 answers

Why do we need stateless widgets if the same can be achieved by stateful widgets in flutter?

I am a newbie in the world of flutter, and I recently learned (or I think I did) about stateful and stateless widgets which is kind of the base for flutter widgets. We use stateless widgets for things that are not redrawn on the display, (like text,…
HexaCrop
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16
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3 answers

Preserve widget state when temporarily removed from tree in Flutter

I'm trying to preserve the state of a widget, so that if I temporarily remove the stateful widget from the widget tree, and then re-add it later on, the widget will have the same state as it did before I removed it. Here's a simplified example I…
Arthur Facredyn
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12
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3 answers

StatefulWidget Page recreate when keyboard is open

In my profile page have edit option when use click edit icon i change Text widget to TextField Widget using Boolean condition like widget.isUpdate ? new Flexible(child: new TextField()) : Text("Text Widget") it working but when TextField focused the…
Magesh Pandian
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9
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3 answers

type '(dynamic) => dynamic' is not a subtype of type '(dynamic) => bool' of 'test' when I use map function

I have a StatefulWidget widget with a LinkedHashMap member done like this: LinkedHashMap _items = new LinkedHashMap>(); Now I need to filter the items inside the List items of the Map. I use this code to…
Giacomo M
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8
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1 answer

Get parent widget height in flutter

I want create statefulWidget and want in this widget get parent widget height. Don't want do this by sending height data from parent widget. How can I do this?
esfsef
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8
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2 answers

Flutter reset StatefulWidget state when Widget is recreated

In my Flutter Widget I have a StreamBuilder that checks for snapshot.hasError and in this specific case it will return my ErrorRetryWidget(). builder: (context, AsyncSnapshot snapshot) { ... if (snapshot.hasError) { return…
Scaraux
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8
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2 answers

How to stop a widget to reload on setState() method in StatefulWidget Class in Flutter

What I am trying to achieve is to save the state of the Widget i.e it should not refresh when the setState() method is been called. class _GenderSelectionPageState extends State { bool isFemaleSelected = false; …
Hitesh Danidhariya
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6
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1 answer

Multiple instances of same Statefulwidget seem to share the same State object?

I'm trying to build an app using Flutter and am running into a small problem. I'm trying to implement a BottomNavigaionBar style app with three pages. (see first snippet) The layout makes use of three objects of type "ChorePage". It seems like the…
Amdixer
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6
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2 answers

Why build method isn't defined inside StatefulWidget?

I'm currently learning Flutter. I tried to deep dive into Flutter Widget life-cycle, and I wonder why StatefulWidget are written like this : class Example extends StatefulWidget { @override _ExampleState createState() =>…
Trần Đức Tâm
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6
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3 answers

How to change a State of a StatefulWidget inside a StatelessWidget?

Just testing out flutter. The code sample below is a very simple flutter app. The problem is that I don't know how to call the setState() function inside the TestTextState class in order to change the text each time when the change button is…
Jakub
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5
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1 answer

Flutter : keep an persistent( timer )widget open and running across multiple screens

I have an app that needs a persistent, across multiple screen timer feature in it, which can be launched from one or two different screens. I can build a timer widget and countdown part. But I can't seem to figure it out how to keep it running and…
lycheelichi
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5
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1 answer

What's the scope of an UniqueKey in flutter?

I'm an unique person. I mean I'm different from all other persons in this world. When I create an UniqueKey in flutter, what's the world in which it's different from all the others?
John Wang
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