Скачать или смотреть Solving the Problem of Dynamically Generating Controls in Blazor

Learn how to effectively create dynamic button controls in Blazor so that each button responds independently without conflicts.
---
This video is based on the question https://stackoverflow.com/q/63725178/ asked by the user 'GettingStarted' ( https://stackoverflow.com/u/399508/ ) and on the answer https://stackoverflow.com/a/63725361/ provided by the user 'Henk Holterman' ( https://stackoverflow.com/u/60761/ ) 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: dynamically generating controls

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

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Solving the Problem of Dynamically Generating Controls in Blazor

When developing applications with Blazor, you might encounter scenarios where you need to generate UI controls dynamically based on items from a collection. A common challenge arises when you want each control, such as a button, to behave independently. For instance, if you create buttons in a loop to display location details, clicking any button may unintentionally trigger the display for all buttons. Let’s break down the issue and see how we can solve it effectively.

The Original Problem

In the code snippet below, each button, when clicked, opens a popover to show details about a particular location. However, clicking any button displays the same popover, indicating that all buttons are linked to a single state management variable.

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

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

What's Going Wrong?

The main issue is that the onclick attribute is the same for all buttons, leading to a shared state. Since the IsOpen1 variable is used across all buttons, when one button is clicked, it opens the popover for all buttons, creating confusion and reducing usability.

The Solution

To ensure that each button only controls its associated popover, we can refactor the code. The primary adjustment involves introducing a unique identifier for each button and managing the open state accordingly.

Step-by-Step Breakdown

Unique Identifiers: Ensure that each button uses a unique identifier—typically achieved by leveraging the properties of the items within the loop.

Modify OnClick Logic: Instead of a single IsOpen variable, utilize a property to track the currently selected schedule ID to determine which popover should be displayed.

Here’s how you can implement this solution:

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

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

Explanation of Changes

Dynamic Target Naming: In the popover’s Target attribute, we create a unique target string based on the schedule ID, ensuring that each button and its corresponding popover are linked correctly.

SelectedId Property: This integer (or nullable type) keeps track of which popover is currently active. By setting it to null, we can easily toggle the currently displayed popover by clicking on the button again.

UI Updates: The StateHasChanged() ensures that the UI reflects the current state, making the interaction smooth.

Conclusion

By adopting unique identifiers and managing state separately for each button, we can resolve the issue of overlapping popover displays in your Blazor applications. This pattern not only makes the code cleaner but also enhances user experience significantly.

Now, you can create dynamic controls that provide a seamless and responsive user interface. Happy coding!