How to Use DropdownButton in Flutter with Custom Display Values

Learn how to customize the displayed values of a Flutter `DropdownButton` using the `selectedItemBuilder` feature for better user experience.
---
This video is based on the question https://stackoverflow.com/q/75503416/ asked by the user 'FetFrumos' ( https://stackoverflow.com/u/631843/ ) and on the answer https://stackoverflow.com/a/75503847/ provided by the user 'Peter Koltai' ( https://stackoverflow.com/u/14726230/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Flutter DropdownButton - Custom title for selected value?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Customizing DropdownButton in Flutter: Displaying Different Values for Selected Items

Flutter is a powerful framework for building beautiful mobile applications. One common element developers often need to implement is a DropdownButton. However, a frequent question arises: How can we display different values in a dropdown's popup list and the selected value in the input field? In this guide, we will tackle this exact problem and show you how to achieve a customized DropdownButton experience in Flutter.

Understanding the Problem

In a typical DropdownButton, when you select an item, the displayed value in the input field is the same as what you see in the dropdown list. However, there might be situations where you want the dropdown to show detailed information, while the input field displays a concise version of that information. For instance, in our scenario, we want to display the fullName along with the shortName in the dropdown, but only the shortName in the selected input field.

Here’s an example of how your model might look:

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

Given the above, let's dive into the solution.

Solution Overview

To achieve our goal, we will use the selectedItemBuilder property of the DropdownButtonFormField. This property allows us to customize how the selected item is displayed. Below are the steps to implement this solution:

Step 1: Define Your Data Model

You need a data model that holds the required information for each item. Here's our model:

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

Step 2: Create Dropdown Items

We will create a method to generate our dropdown items based on the model. The dropdown will display both the fullName and the shortName.

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

Step 3: Implement the DropdownButton

Now, let’s implement the DropdownButtonFormField in our widget. Here, you will leverage the selectedItemBuilder to customize what is shown in the input field.

Here's how you can set it up:

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

Full Example Code

Here’s the complete code wrapped together for better understanding:

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

Conclusion

Customizing the DropdownButton in Flutter to show different values for selected items and in the dropdown is straightforward with the selectedItemBuilder property. By following the steps outlined above, you can improve your app's usability and give users the clear information they need when selecting from a list.

Final Thoughts

Experiment with customizing dropdowns in your Flutter applications, and feel free to extend the logic further to meet your specific needs. Happy coding!

Видео How to Use DropdownButton in Flutter with Custom Display Values канала vlogize