How To Change Flutter Textfield Focused Border Color [Easy Flutter Guide]

In this tutorial, we’ll learn what Flutter textfield focused border color is and how to properly change it. We’ll be using practical Flutter code examples for better understanding.

Introduction: Flutter Textfield Focused Border Color

Focused border is the border that is shown when the textfield is focused. Let’s first see its default color and after that, we’ll customize it practically.

Default Focused Border Color

For that, we’ll implement a simple Flutter textfield widget. By default, the textfield is assigned with underline border which we’ll see in the below image after our code gets executed. See below code:

TextField()

The above image shows the default Flutter textfield focused border color. Let’s now see how to customize its color.

Change Flutter Textfield Focused Border Color

• In order to do that, we’ve to use the decoration constructor of textfield widget class and pass it input decoration.
• After that, we’ll use the focused border constructor of input decoration and pass it underline input border as we are currently customizing the underline border color.
• Finally, we’ve to use the border side constructor of underline input border and pass it border side widget and then by using its color constructor, we can easily pass it any color of our choice. For demonstration, we’ve passed it a green color.
• Also, we’ve increased the height of border using the width constructor of border side class so the color change will look more visible. See below code:

TextField(
        decoration: InputDecoration(
            focusedBorder: UnderlineInputBorder(
                borderSide: BorderSide(
                     color: Colors.green, 
                     width: 2))),
      )

As we can see that Flutter textfield focused border color is successfully customized.

See below code if you want to change the outline border color of textfield.

TextField(
      decoration: InputDecoration(
          focusedBorder: OutlineInputBorder(
              borderSide: BorderSide(
                   color: Colors.green, 
                   width: 2))),
      )

So this is how we can easily change Flutter textfield focused border color.

Click here if you are interested in learning the color customization of Flutter textfield focused border width.

The complete source code of custom focused border color is given in the below section.

Custom Flutter Textfield Focused Border Color Source Code

import 'package:flutter/material.dart';
void main() {
  runApp(const MyApp());
}
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Homepage(),
    );
  }
}
class Homepage extends StatefulWidget {
  @override
  State<Homepage> createState() => _HomepageState();
}
class _HomepageState extends State<Homepage> {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
        child: Scaffold(
            body: Center(
                child: Padding(
      padding: const EdgeInsets.all(20),
      child: TextField(
        decoration: InputDecoration(
           focusedBorder: UnderlineInputBorder(
                borderSide: BorderSide(color: Colors.green, width: 2))),
      ),
    ))));
  }
}