Quick Fix: Within the @page directive, incorporate @rendermode InteractiveServer to facilitate interactive communication between the Blazor UI (written in C#) and the underlying C# code. This will enable the onchange event to function as intended.
The Problem:
A newcomer to Blazor is experiencing issues with the onchange event of a select control not firing in their Blazor app. The objective is to execute specific logic upon the user’s selection in the select control. The developer has attempted to use both the onchange and onselect events, but neither seems to be triggering the desired event handling function. The provided code demonstrates the usage of these events within the Blazor component, alongside the GroupSelected() method intended to handle the event. Assistance is sought to resolve this issue and enable successful execution of code when a selection is made in the select control.
The Solutions:
Solution 1: Add @rendermode InteractiveServer
To make the `onchange` event of the `select` control work, you need to enable interactive server-side rendering in your Blazor app. Add the following line after the `@page` directive in your Razor component:
“`
@rendermode InteractiveServer
“`
This tells the Blazor compiler to use a technique called “interactive server-side rendering,” which allows the server to communicate with the client (the user’s web browser) more frequently and efficiently. This enables features like real-time updates and event handling, which are essential for making the `onchange` event work.
With this change, the `onchange` event of your `select` control should now fire when the user makes a selection, and the `GroupSelected` method will be called as expected.
Q&A
Event onchange is not firing. What am I missing in my code?
—
Add directive @rendermode InteractiveServer after @page
Can you detail what the @rendermode InteractiveServer directive does?
—
It enables interactive communication with the server for updating the UI
Video Explanation:
The following video, titled "Blazor Cascading Dropdown Not Working with InputSelect - YouTube", provides additional insights and in-depth exploration related to the topics discussed in this post.
In this video, I get to fix the code of a very good friend of mine, Mr. Jerry Nixon. Jerry recently reached out to me and asked why his ...
