flutter/dart

Feb 11

[Flutter/Dart] Format string with TextField

What want to do I want to create an input form using TextField. For example, if the input content is a monetary amount, I would like to...

Feb 11

[Flutter/dart] Check if late variable is initialized

What want to do There is a variable that remain unchanged once the initial value is determined. However, it cannot be determined yet when...

Oct 22, 2023

[Flutter/Dart] Place widgets in the middle and right edge of the screen

What want to do As the title suggests. Place two widgets in one line on the screen One in the center of the screen and the other on the...

Sep 9, 2023

[Flutter/dart]GestureDetector event runs when page is displayed

Phenomenon Certain icons perform certain actions when long-pressed To achieve this, I registered the actions in GestureDetector's...

Sep 9, 2023

[Flutter/dart] Support item deletion with Redux pattern

Background Consider the following case. There is a list of items There is a page that displays details for a specific item. You can...

Jul 17, 2023

[Flutter/Dart] Numbering of id when adding a new item

Issue Assumptions Register and save multiple items Items are managed with a unique id State management is redux The flow of adding a new...

Jul 16, 2023

[Flutter/Dart] Initialize state with remote database data in redux

Things to do Use Redux for state management. Let the state be AppState. Start acquiring data from remote database when app starts Get...

Jul 16, 2023

[Flutter/Dart] Different view while waiting for image acquisition

Things to do There is a widget that displays an image Images are acquired from remote storage Because it takes time, I would like to...

Jul 13, 2023

[Flutter/Dart] Scroll part + fixed at the bottom

What want to do Characters A list of some items (hereafter ListView) Some Widget (hereafter text) Layout Text is fixed at the bottom of...

Jul 10, 2023

[Flutter/Dart] Countermeasure when you want to perform asynchronous process in the constructor

Problem There are times when you want to do asynchronous process in the constructor of a Dart class. For example, the initial value is...

Jul 10, 2023

[Flutter/Dart] Unhandled Exception: PlatformException(sign_in_failed, com.google.android.gms....

Phenomenon When I try to sign in to Firebase with google_sign_in, it fails with the following error. Unhandled Exception:...

Jul 10, 2023

[Flutter/Dart] Hot Restart builds the whole app twice

Phenomenon When hot restart the Flutter runApp(MyApp()); runs twice (checked with debugger). It seems this issue is only for Hot Restart....

Jul 10, 2023

[Flutter/dart] Method 'addPostFrameCallback' cannot be called on 'WidgetsBinding?' because ...

Phenomenon When I try to build with Flutter I get the following error Method 'addPostFrameCallback' cannot be called on 'WidgetsBinding?'...

Dec 31, 2022

[Flutter/dart]initialization error of Admob

Phenomenon When Admob is added in the app and the app is started, the following error occurs. java.lang.RuntimeException: Unable to get...

Dec 31, 2022

[Flutter/dart]Conversion from Uri toUrl

Overview When I have a Uri and want to convert it to a Url, I'm a little confused, so I'll share. Method String url = uri.toString();...

Dec 31, 2022

[Fluter/dart]Just adding the factory keyword does not generate singleton

Overview In dart, you can add the factory keyword to the constructor. I made the following mistake. A factory constructor is for creating...

Dec 30, 2022

[Flutter/dart]createState() and initState() are not called when a StatefulWidget is rebuilt from its

Oveview There is a generic StatefulWidget like below. class childWidget extends StatefulWidget{ State<StatefulWidget> createState() {...

Dec 29, 2022

[Flutter/dart] Default value of a class instance in null safety

Overview When creating an instance of a certain class, there are cases where it is optional to set arguments to the instance, and if not...

Nov 30, 2022

[Flutter/dart] Private and final class variable

Overview Suppose adding a class variable in dart like below. Private (don't want to be accessed from outside) Determine the value by...

Apr 4, 2022

[Flutter/dart] The method at notification tapping does not work when the app is terminated

Phenomenon Create a notification using flutter_local_notification. The method when tapping the notification is also registered. If the...