dart - How to change the value inside of a textfield flutter?

Dart - How to change the value inside of a textfield flutter?

To change the value inside a TextField widget in Flutter, you need to use a TextEditingController. Here's how you can do it:

import 'package:flutter/material.dart'; void main() { runApp(MyApp()); } class MyApp extends StatelessWidget { // Create a TextEditingController final TextEditingController _controller = TextEditingController(); @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar( title: Text('TextField Example'), ), body: Center( child: Padding( padding: EdgeInsets.all(16.0), child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ TextField( controller: _controller, // Assign the controller to the TextField decoration: InputDecoration( hintText: 'Enter text here', ), ), ElevatedButton( onPressed: () { // Set the new value of the TextField _controller.text = 'New value'; }, child: Text('Change Text'), ), ], ), ), ), ), ); } }

In this example:

  • We create a TextEditingController named _controller.
  • We assign this controller to the TextField widget using the controller property.
  • To change the value inside the TextField, we can simply modify the text property of the controller (_controller.text). In the onPressed event handler of the button, we set the text to a new value ('New value').

This will update the value displayed in the TextField. You can also listen to changes in the text field by adding a listener to the controller if needed.

Examples

  1. Query: "Flutter TextEditingController to set TextField value"

    • Description: This query discusses how to use a TextEditingController to programmatically set or change the text inside a TextField.
    • Code:
      TextEditingController _controller = TextEditingController(text: "Initial Text"); TextField( controller: _controller, decoration: InputDecoration(labelText: "TextField"), ); _controller.text = "Updated Text"; // Change text

  2. Query: "Flutter set TextField value on button press"

    • Description: This query explores how to set the value of a TextField when a button is pressed.
    • Code:
      TextEditingController _controller = TextEditingController(); ElevatedButton( onPressed: () { _controller.text = "New Value"; // Set TextField value }, child: Text("Set TextField Value"), ); TextField( controller: _controller, decoration: InputDecoration(labelText: "Press Button to Change"), );

  3. Query: "Flutter set TextField value with focus change"

    • Description: This query discusses changing the TextField's value when it gains or loses focus.
    • Code:
      FocusNode _focusNode = FocusNode(); TextEditingController _controller = TextEditingController(); _focusNode.addListener(() { if (!_focusNode.hasFocus) { _controller.text = "Focus Lost"; // Change text when focus is lost } }); TextField( controller: _controller, focusNode: _focusNode, decoration: InputDecoration(labelText: "Focus Change"), );

  4. Query: "Flutter set TextField value with delay or timer"

    • Description: This query explores setting the value of a TextField after a delay using a timer.
    • Code:
      import 'dart:async'; TextEditingController _controller = TextEditingController(); Timer(Duration(seconds: 3), () { _controller.text = "Value after 3 seconds"; // Set text after delay }); TextField( controller: _controller, decoration: InputDecoration(labelText: "Delayed Text"), );

  5. Query: "Flutter set TextField value from another widget"

    • Description: This query explores how to set a TextField's value from a different widget, demonstrating inter-widget communication.
    • Code:
      class ParentWidget extends StatelessWidget { final TextEditingController _controller = TextEditingController(); @override Widget build(BuildContext context) { return Column( children: [ ChildWidget(controller: _controller), TextField( controller: _controller, decoration: InputDecoration(labelText: "Controlled TextField"), ), ], ); } } class ChildWidget extends StatelessWidget { final TextEditingController controller; ChildWidget({required this.controller}); @override Widget build(BuildContext context) { return ElevatedButton( onPressed: () { controller.text = "Set from Child"; // Set TextField from another widget }, child: Text("Change Parent Text"), ); } }

  6. Query: "Flutter set TextField value with user interaction"

    • Description: This query explores changing the TextField's value based on user interaction, like toggling a checkbox or selecting a dropdown item.
    • Code:
      TextEditingController _controller = TextEditingController(); bool _isToggled = false; Checkbox( value: _isToggled, onChanged: (value) { _isToggled = value!; _controller.text = _isToggled ? "Checkbox Checked" : "Checkbox Unchecked"; // Set text on checkbox toggle }, ); TextField( controller: _controller, decoration: InputDecoration(labelText: "Dynamic TextField"), );

  7. Query: "Flutter TextField with initial value from shared preferences"

    • Description: This query discusses how to set a TextField's value based on a value retrieved from shared preferences (persistent storage).

    • Code:

      # Add the shared_preferences package to pubspec.yaml dependencies: shared_preferences: ^2.0.18

    • Usage:

      import 'package:shared_preferences/shared_preferences.dart'; TextEditingController _controller = TextEditingController(); Future<void> _loadInitialValue() async { SharedPreferences prefs = await SharedPreferences.getInstance(); _controller.text = prefs.getString('storedText') ?? "Default Text"; // Set initial value from shared preferences } @override void initState() { super.initState(); _loadInitialValue(); // Load initial value } TextField( controller: _controller, decoration: InputDecoration(labelText: "TextField with Shared Preferences"), );

  8. Query: "Flutter TextField value binding with provider"

    • Description: This query explores using provider to manage and update the TextField's value in a Flutter app with state management.

    • Code:

      # In pubspec.yaml, add the provider package dependencies: provider: ^6.0.5

    • Usage:

      import 'package:flutter/material.dart'; import 'package:provider/provider.dart'; class TextProvider extends ChangeNotifier { String _text = ""; String get text => _text; void updateText(String newText) { _text = newText; notifyListeners(); } } void main() { runApp( ChangeNotifierProvider( create: (_) => TextProvider(), child: MyApp(), ), ); } class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: Text("Provider Example")), body: Column( children: [ Consumer<TextProvider>( builder: (context, textProvider, child) { return TextField( controller: TextEditingController(text: textProvider.text), onChanged: (value) { textProvider.updateText(value); // Bind value with provider }, decoration: InputDecoration(labelText: "Provider TextField"), ); }, ), ElevatedButton( onPressed: () { Provider.of<TextProvider>(context, listen: false).updateText("Updated from Button"); }, child: Text("Update with Button"), ), ], ), ); } }

  9. Query: "Flutter TextField reset value"

    • Description: This query explores how to reset the value in a TextField, useful for creating clear buttons or resetting form inputs.
    • Code:
      TextEditingController _controller = TextEditingController(text: "Some Text"); ElevatedButton( onPressed: () { _controller.clear(); // Clear the TextField value }, child: Text("Reset TextField"), ); TextField( controller: _controller, decoration: InputDecoration(labelText: "Resettable TextField"), );

  10. Query: "Flutter set TextField value with validation"

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