Скачать или смотреть How to Change the Background Color of a Text Field in Flutter Based on Focus and Content State

Discover how to dynamically change the `background color` and `border` of a Text Form Field in Flutter when the field is in focus, unfocused, or empty.
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This video is based on the question https://stackoverflow.com/q/64304006/ asked by the user 'Shahryar Rafique' ( https://stackoverflow.com/u/13203445/ ) and on the answer https://stackoverflow.com/a/64305307/ provided by the user 'Zaza.codes' ( https://stackoverflow.com/u/11172951/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Changing Text Form Field Colors in Flutter: A Comprehensive Guide

When developing user interfaces in Flutter, creating engaging and interactive form fields can significantly enhance user experience. One common requirement is to change the background color of a TextFormField based on its state—whether it is focused, unfocused, or empty. If you've ever found yourself wondering, "How can I achieve this effect?", you're in the right place! Let's explore how to implement this functionality effectively.

Understanding the Problem

In many applications, it's beneficial to provide visual feedback to users as they interact with form elements. Specifically, you might want your text form field to:

Change its background color when tapped (focused).

Change color when it is empty (unfocused).

Update its look as content is entered.

This dynamic behavior not only makes the application visually appealing but also improves usability.

Solution Overview

To achieve the desired functionality, we can use the setState method along with the onTap and other relevant properties of the TextFormField. Below, I will guide you step by step through the implementation process.

Step-by-Step Implementation

Declare Your Variables:
Start by creating variables for the background color and border color of your TextFormField. These will be updated based on the field's state.

[[See Video to Reveal this Text or Code Snippet]]

Create Your TextFormField:
Next, set up your TextFormField widget. Use the decoration property to customize the appearance:

[[See Video to Reveal this Text or Code Snippet]]

Wrap It in a Stateful Widget:
Since we are using setState, make sure to place the TextFormField inside a StatefulWidget. This enables the widget to rebuild and reflect the changes in color dynamically.

[[See Video to Reveal this Text or Code Snippet]]

Key Points to Remember

State Management: Always ensure to keep track of states properly using setState.

Visual Feedback: Users appreciate clear visual cues. Changing colors based on field state keeps the interface user-friendly.

Customization: Feel free to adjust colors or borders for your design preferences.

Conclusion

Implementing dynamic feedback for a TextFormField in Flutter is not only straightforward but also essential for creating a polished user interface. By utilizing the setState method, you can easily control the appearance of the form field based on its focus and content state.

Feel free to experiment with different colors and conditions based on your application needs. Happy coding!