Kaia  Schmitt

Kaia Schmitt

1632330000

instructions on How to Increase and Decrease an Item In ListView

In this lesson, you'll learn about: instructions on How to Increase and Decrease an Item In ListView
#listview #flutter 

instructions on How to Increase and Decrease an Item In ListView

A Modification Of Flutter's ListView and ReorderableListView

known_extents_list_view_builder

See the difference

Watch this video taken in release mode.

About

This package is intended to address a performance issue in Flutter. Whereas the internal flutter list only allows you to pass in a fixed itemExtent to optimize for uniform lists, this allows you to pass in a list of itemExtents for when your list items have variable (though knowable) extents. Includes a basic list and a reorderable list.

Examples

Find examples of the basic list and of the reorderable lists side by side as shown in the video in examples/lib.

Using ReorderableDragStartListener

If you want to turn off default drag handles and create your own or wrap your widget in ReorderableDragStartListener or ReorderableDelayedDragStartListener, be sure to import the listener from this library's known_extents_sliver_reorderable_list and not from flutter/widgets. For example, if using ReorderableDragStartListener, your imports might look like this:

import 'package:flutter/material.dart' hide ReorderableDragStartListener;
import 'package:known_extents_list_view_builder/known_extents_reorderable_list_view_builder.dart';
import 'package:known_extents_list_view_builder/known_extents_sliver_reorderable_list.dart' show ReorderableDragStartListener;

Disclaimer

This is not official Flutter package, nor is it put out by the Flutter team. Maintainance and edges cases are not guaranteed.

If you don't need your list to be reorderable, and would prefer to scroll to indexes rather than exact pixel values, consider using scrollable_positioned_list.

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add known_extents_list_view_builder

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):


dependencies:
  known_extents_list_view_builder: ^1.0.3

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:known_extents_list_view_builder/known_extents_list_view_builder.dart'; 

example/lib/example.dart

import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:known_extents_list_view_builder/known_extents_reorderable_list_view_builder.dart';
// This example shows two reorderable lists side by side.
// For a basic example with a non-reorderable list see basic_list.dart

void main() {
  runApp(MyApp());
}

JsonEncoder encoder = new JsonEncoder.withIndent('  ');

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Known Extents Demo: 10,000 items side by side'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: LayoutBuilder(
            builder: (BuildContext context, BoxConstraints constraints) {
          return Row(
            children: [
              ListDisplay(constraints: constraints, useKnownExtents: false),
              ListDisplay(constraints: constraints, useKnownExtents: true),
            ],
          );
        }));
  }
}

class ListDisplay extends StatefulWidget {
  final bool useKnownExtents;
  final BoxConstraints constraints;
  const ListDisplay(
      {Key? key, required this.constraints, required this.useKnownExtents})
      : super(key: key);

  @override
  _ListDisplayState createState() => _ListDisplayState();
}

class _ListDisplayState extends State<ListDisplay> {
  late ScrollController scrollController;
  @override
  void initState() {
    scrollController = ScrollController();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    final title =
        widget.useKnownExtents ? 'Using Known Extents' : 'No Optimization';
    return Column(
      children: [
        Center(
          child: Padding(
            padding: const EdgeInsets.all(8.0),
            child: Text(
              title,
              style: TextStyle(fontSize: 25),
            ),
          ),
        ),
        Padding(
            padding: const EdgeInsets.all(8.0),
            child: ScrollButtons(controller: scrollController)),
        ConstrainedBox(
          constraints: BoxConstraints(
              maxHeight: widget.constraints.maxHeight - 112,
              maxWidth: widget.constraints.maxWidth / 2),
          child: Padding(
            padding: const EdgeInsets.all(8.0),
            child: ExampleList(
              useKnownExtents: widget.useKnownExtents,
              scrollController: scrollController,
            ),
          ),
        ),
      ],
    );
  }
}

class ScrollButtons extends StatefulWidget {
  final ScrollController controller;
  const ScrollButtons({required this.controller, Key? key}) : super(key: key);

  @override
  _ScrollButtonsState createState() => _ScrollButtonsState();
}

class _ScrollButtonsState extends State<ScrollButtons> {
  final textController = TextEditingController(
    text: '500000',
  );
  bool animate = false;
  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: 300,
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceAround,
        children: [
          Switch(
              value: animate,
              onChanged: (b) {
                setState(() {
                  animate = b;
                });
              }),
              Spacer(),
          TextButton(
              onPressed: () {
                if (animate) {
                  widget.controller.animateTo(double.parse(textController.text),
                      duration: Duration(milliseconds: 500), curve: Curves.ease);
                } else {
                  widget.controller.jumpTo(double.parse(textController.text));
                }
              },
              child: animate ? Text('Animate to') : Text('Jump to')),
          Spacer(
            flex: 1,
          ),
          SizedBox(
            width: 100,
            child: TextField(
              textAlign: TextAlign.center,
              decoration: InputDecoration(
                  border: UnderlineInputBorder(), labelText: 'pixels'),
              keyboardType: TextInputType.number,
              controller: textController,
            ),
          )
        ],
      ),
    );
  }
}

class ExampleList extends StatefulWidget {
  final ScrollController scrollController;
  final bool useKnownExtents;
  ExampleList({this.useKnownExtents = true, required this.scrollController});
  @override
  _ExampleListState createState() => _ExampleListState();
}

class _ExampleListState extends State<ExampleList> {
  static List<Map<String, dynamic>> items = List.generate(
      10000,
      (index) => (index % 5 == 0)
          ? {'text': 'header', 'id': index}
          : {'text': "List Item: $index", 'id': index});

  late ScrollController scrollController;
  final double _itemHeight = 60.0;
  final double _headerHeight = 21.0;
  Widget _itemBuilder(_, index) {
    final item = items[index];
    if (item['text'] != 'header') {
      return Container(
          width: Size.infinite.width,
          height: _itemHeight,
          key: ValueKey(items[index]),
          color: Colors.blueGrey.shade100,
          child: Center(child: Text(item['text'])));
    } else {
      return Container(
          color: Colors.blueGrey.shade900,
          width: Size.infinite.width,
          key: ValueKey(items[index]),
          child: Center(
              child: Text(item['text'], style: TextStyle(color: Colors.white))),
          height: _headerHeight);
    }
  }

  List<double> makeItemExtents() {
    final _result = items.map((item) {
      if (item['text'] == 'header') {
        return _headerHeight;
      }
      return _itemHeight;
    }).toList();
    return _result;
  }

  @override
  void initState() {
    scrollController = widget.scrollController;
    super.initState();
  }

  _onReorder(int start, int end) {
    setState(() {
      items.insert(end, items[start]);
      if (start > end) {
        start += 1;
      }
      items.removeAt(start);
    });
  }

  _contents() {
    if (widget.useKnownExtents) {
      return KnownExtentsReorderableListView.builder(
        onReorder: _onReorder,
        itemExtents: makeItemExtents(),
        physics: ClampingScrollPhysics(),
        itemCount: items.length,
        scrollController: scrollController,
        itemBuilder: _itemBuilder,
      );
    } else {
      return ReorderableListView.builder(
        onReorder: _onReorder,
        physics: ClampingScrollPhysics(),
        itemCount: items.length,
        scrollController: scrollController,
        itemBuilder: _itemBuilder,
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return _contents();
  }
} 

Download Details:

Author: bendelonlee

Source Code: https://github.com/bendelonlee/known_extents_list_view_builder

#flutter #listview  #reorderablelistview 

 

A Modification Of Flutter's ListView and ReorderableListView
Marisol  Kuhic

Marisol Kuhic

1627405200

Flutter : Expandable listview tutorial for beginners

#Flutter #Expandable #listview is explained in this part of the tutorial.

Source Code : http://www.androidcoding.in/2020/09/07/flutter-expandable-listview/

Android - Kotlin Complete Course:

Kotlin Introduction : https://youtu.be/2_EXYeKVX3g
Kotlin Variables & Data Types : https://youtu.be/bevfj0pFH6Q
Kotlin If-Conditions : https://youtu.be/8r0TMiKLwGo
Kotlin When Condition (Switch) : https://youtu.be/oQ3rXxU2bK4
Kotlin For Loop : https://youtu.be/10uMCFiUDNU
Kotlin While & Do-While Loop : https://youtu.be/nXStQ8WFCT0

#beginners #flutter #listview

Flutter : Expandable listview tutorial for beginners
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Marisol Kuhic

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Implementation of a Flutter swipeable listview for beginners

#Flutter #slidable #listview implementation is explained in this tutorial.

Source Code : http://www.androidcoding.in/2020/09/07/flutter-slidable/

Visit my website :

http://androidcoding.in/

#beginners #flutter #listview

Implementation of a Flutter swipeable listview for beginners
Kaia  Schmitt

Kaia Schmitt

1627162260

Flutter ListView | How to Create Different Types of ListView Layout | Flutter

Learn How to Create Different Types of ListView Layout in Flutter | ListView In Flutter | CodeStudio.

GitHub - https://github.com/theindianinnovation/

#flutter #layout #listview #flutter listview

Flutter ListView | How to Create Different Types of ListView Layout | Flutter

How to Master Custom Listview with Item Click in android for Beginners

In This Guide, learn about How to Master Custom Listview with Item Click in android for Beginners

Hey Developers,
In this video, I have explained :

  • How to implement Custom List view in Android
  • How to implement Itemclicklistener on custom list view

#listview #android

How to Master Custom Listview with Item Click in android for Beginners

How to Custom ListView with item click using Kotlin in Android for Beginners

In This Guide, learn about How to Custom ListView with item click using Kotlin in Android for Beginners

Hey Developers,
In this video, I have explained :

  • How to implement Custom List view in Android using Kotlin
  • How to implement Itemclicklistener on the custom list view using Kotlin

#android #kotlin #listview

How to Custom ListView with item click using Kotlin in Android  for Beginners
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Elliott Owen

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Exploring Flutter Widgets || Flutter Dynamic List View & pubspec.yaml file #10

In this video I have discussed how to use memory efficient dynamic list view by using ListView.builder constructor. I have also discussed about pubspec.yaml file.

#listview #flutter

Exploring Flutter Widgets || Flutter Dynamic List View & pubspec.yaml file #10
Rowena  Cox

Rowena Cox

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Using Xamarin.Forms SwipeView + CollectionView Bonus!

Since touchscreens the swipe gesture is suddenly a thing! Luckily Xamarin.Forms now has the SwipeView. With SwipeView you can swipe basically any visual element on screen. There is lots of events and properties to customize the whole experience to your needs.

In this video we will see how to use SwipeView and how to apply it to a CollectionView.

🔗 Links
Sample code: https://github.com/jfversluis/XFSwipeViewSample
DataTemplate Video: https://www.youtube.com/watch?v=O0Ym-x8joqg
Data Binding Playlist: https://www.youtube.com/watch?v=Or_qn8i8jVM&list=PLfbOp004UaYWOuVUuEtGlpkDIC1houhn_

Xamarin Forms Repo: https://github.com/xamarin/Xamarin.Forms
Xamarin.Forms SwipeView Docs: https://docs.microsoft.com/xamarin/xamarin-forms/user-interface/swipeview

⏱ Timestamps
0:00 Intro
0:22 Sample App Outline
1:00 Start Implementing SwipeView
1:45 Explore SwipeView APIs
2:35 Implement SwipeItem
4:40 Customize SwipeItem Behavior
9:20 Programatically Open and Close SwipeItems
9:50 SwipeView IsEnabled
10:10 Using SwipeView with CollectionView
15:10 Outro

#listview #swipeview #xamarinforms #collectionview

Using Xamarin.Forms SwipeView + CollectionView Bonus!
Vada  Dare

Vada Dare

1625825940

ListView & ListView.builder Explained (+ How To Use It) - Flutter

ListView or ListView.builder, which one to use and how to use them?

Well, many times in your Flutter journey, you’ll need to use lists. I

f you need to use a really big and huge list, ListView.builder() is your friend!

Not only will it make your app perform better, it will remarkably shorten the amount of code you’ll need.

Now the regular ListView is also useful, of course. But only for short/small predictable lists.

If you don’t know in advance how many items a list will have, always go with a ListView.builder, as it will only render what is visible in the viewport, making the entire process much more optimal. Thanks Flutter team!

ListView Class official documentation: https://api.flutter.dev/flutter/widgets/ListView-class.html

00:00 - Intro
00:25 - Documentation Definition Explained
01:47 - Learning By Doing
02:30 - ListView Example (+ Spread Operator)
03:03 - ListView Error Example
03:40 - ListView “reverse” Property
04:12 - ListView.builder Explained
07:00 - ListView.builder Usage Example
08:18 - ListView.builder Error Example
08:49 - Like & Subscribe
09:06 - Flutter Mentor Out

#flutter #listview #listviewbuilder

Credits:

OUTRO SONG:
Mitsubachi by Smith The Mister https://smiththemister.bandcamp.com
Smith The Mister https://bit.ly/Smith-The-Mister-YT
Free Download / Stream: http://bit.ly/mitsubachi
Music promoted by Audio Library https://youtu.be/0IgndUb1YQI

#flutter #listview #listviewbuilder

ListView & ListView.builder Explained (+ How To Use It) - Flutter
Andre  Fisher

Andre Fisher

1625450892

ListView in Xamarin Forms (Add, Update, Delete) - Ep:11

How to Add, Update or Delete Item From Xamarin List View using Visual Studio 2019.
👉FOLLOW US ON:
Facebook: https://www.facebook.com/ashproghelp
My Blog: http://ashproghelp.blogspot.com

👉Create First Android App using Xamarin Forms & Visual Studio 2019 :
https://youtu.be/sfMdnIUzYJI

👉Xamarin Forms - Android app Development Playlist:

https://youtube.com/playlist?list=PLprnOV9ZLFnvA_vzjdvfs-lwWfP_8frOW

👉ASP.NET Core Tutorial Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnscrKZoHtAJvl1hsP_rpyIH

👉ASP.NET Core WEB API Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnsR9fB624xD8uk0tIOyByl4

👉Blazor Tutorial Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnt_W3qsBAgxvwgQ4NBNJmvx

👉ASP.NET Core Authentication Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnv0ZYY0bJT2LMukEN634fiD

👉SignalR Tutorials Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnuKYOOXw_NE9RM5UcPmM-yp

👉KENDO UI Tutorials (WEB DEVELOPMENT) Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFns32TRnvTr7FgrPQH8kMog6

👉KENDO UI in ASP.NET Core Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnsoYCrjDuNmWxmWm5WRBXY1

👉Files or Image Upload Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnsFxlwKs-tOs13kqpakWI9e

👉==========AMCHARTS GRAPH JQUERY PLAYLIST==========
https://www.youtube.com/playlist?list=PLprnOV9ZLFnsGDKm_5W__HErKwGl3H1wu

👉=================RDLC Report PlayList===============
https://www.youtube.com/playlist?list=PLprnOV9ZLFnswiKegU95eTyu7nc_YSZmT

👉=================RDLC PRINT===============
How to print without showing report viewer in RDLC report - C#
https://www.youtube.com/watch?v=uTzwk6zBdQs

👉=================RDLC & Crystal Report===============
https://www.youtube.com/playlist?list=PLprnOV9ZLFnsTnvqGApmsCJqdOi15MVdE

👉=================SQL Server Tutorials (Series)===============
https://www.youtube.com/playlist?list=PLprnOV9ZLFntdSaPFBcMMc89XnH8gfRNy

👉=========TEAM FOUNDATION SERVER=============
TFS source control for beginners:
https://www.youtube.com/watch?v=AjhNxCUTEio

👉==========ANDROID APP DEVELOPMENT============
Quick Learn Android full basic in 45 minutes:
https://www.youtube.com/playlist?list=PLprnOV9ZLFntpdZb7cMvpHGE4YBzPDZJY

👉=================C# Basic=============================
https://www.youtube.com/playlist?list=PLprnOV9ZLFnvpVNZT6WFJeUAuVBNny9Pp

#XamarinListView #ListView #XamarinForms #AshProgHelp

#xamarin #listview #xamarin forms

ListView in Xamarin Forms (Add, Update, Delete) - Ep:11
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How to use a ListView in Xamarin Forms using Visual Studio 2019.
How to Bind Data in ListView in MVVM way in Xamarin Forms.

👉FOLLOW US ON:
Facebook: https://www.facebook.com/ashproghelp
My Blog: http://ashproghelp.blogspot.com

👉Create First Android App using Xamarin Forms & Visual Studio 2019 :
https://youtu.be/sfMdnIUzYJI

👉Xamarin Forms - Android app Development Playlist:

https://youtube.com/playlist?list=PLprnOV9ZLFnvA_vzjdvfs-lwWfP_8frOW

👉ASP.NET Core Tutorial Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnscrKZoHtAJvl1hsP_rpyIH

👉ASP.NET Core WEB API Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnsR9fB624xD8uk0tIOyByl4

👉Blazor Tutorial Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnt_W3qsBAgxvwgQ4NBNJmvx

👉ASP.NET Core Authentication Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnv0ZYY0bJT2LMukEN634fiD

👉SignalR Tutorials Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnuKYOOXw_NE9RM5UcPmM-yp

👉KENDO UI Tutorials (WEB DEVELOPMENT) Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFns32TRnvTr7FgrPQH8kMog6

👉KENDO UI in ASP.NET Core Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnsoYCrjDuNmWxmWm5WRBXY1

👉Files or Image Upload Playlist:

https://www.youtube.com/playlist?list=PLprnOV9ZLFnsFxlwKs-tOs13kqpakWI9e

👉==========AMCHARTS GRAPH JQUERY PLAYLIST==========
https://www.youtube.com/playlist?list=PLprnOV9ZLFnsGDKm_5W__HErKwGl3H1wu

👉=================RDLC Report Playlist===============
https://www.youtube.com/playlist?list=PLprnOV9ZLFnswiKegU95eTyu7nc_YSZmT

👉=================RDLC PRINT===============
How to print without showing report viewer in RDLC report - C#
https://www.youtube.com/watch?v=uTzwk6zBdQs

👉=================RDLC & Crystal Report===============
https://www.youtube.com/playlist?list=PLprnOV9ZLFnsTnvqGApmsCJqdOi15MVdE

👉=================SQL Server Tutorials (Series)===============
https://www.youtube.com/playlist?list=PLprnOV9ZLFntdSaPFBcMMc89XnH8gfRNy

👉=========TEAM FOUNDATION SERVER=============
TFS source control for beginners:
https://www.youtube.com/watch?v=AjhNxCUTEio

👉==========ANDROID APP DEVELOPMENT============
Quick Learn Android full basic in 45 minutes:
https://www.youtube.com/playlist?list=PLprnOV9ZLFntpdZb7cMvpHGE4YBzPDZJY

👉=================C# Basic=============================
https://www.youtube.com/playlist?list=PLprnOV9ZLFnvpVNZT6WFJeUAuVBNny9Pp

#ListView #XamarinListView #XamarinForms #AshProgHelp

#xamarin #listview #xamarin forms

ListView in Xamarin Forms | ListView Databind in MVVM - Ep:10

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Binding Data to Blazor ListView Using Entity Framework

The Syncfusion Blazor ListView Component is a list-like interface that allows you to select an item or multiple items. It represents data in an interactive hierarchical structure across different layouts or views.

  • Built-in support for flexible data binding, sorting, grouping, nested navigation, multiple selection, templating, and more.
  • This high-performance Component can load a huge amount of data on demand while being scrolled.
  • Data can be elegantly visualized with cards, images, icons, avatars, and badge representation for better understanding.

Learn how to bind data easily in the Blazor ListView control using Entity Framework.
Download an example from GitHub:
https://bit.ly/3nt6U0I

Learn how to configure the Entity Framework in a Blazor WebAssembly app:
https://bit.ly/34G1Q0y

https://www.youtube.com/watch?v=iEM_W4HP9pk

#blazor #listview #web-development #framework #webassembly

Binding Data to Blazor ListView Using Entity Framework

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Blazor ListView - High-Performance Component

Overview
The Blazor ListView Component is a list-like interface that allows you to select an item or multiple items. It represents data in an interactive hierarchical structure across different layouts or views.

  • Built-in support for flexible data binding, sorting, grouping, nested navigation, multiple selection, templating, and more.
  • This high-performance Component can load a huge amount of data on demand while being scrolled.
  • Data can be elegantly visualized with cards, images, icons, avatars, and badge representation for better understanding.

https://www.syncfusion.com/blazor-components/blazor-listview

#blazor #listview #web-development #component

Blazor ListView - High-Performance Component