How to Pass Parameters in Blazor

Question

Hi,
how can I use something like CommandParameter in Xamarin, but in Blazor
for example:

<div x-index="3" y-index="2"/>

Then access them programmaticaly in C#.

Thanks in advance

Answer 1

I found a solution using Blazor components

Answer 2

I think Blazor data binding is what you need to learn.

https://learn.microsoft.com/en-us/aspnet/core/blazor/components/data-binding?view=aspnetcore-9.0

Using your example markup, the x-index and y-index are assigned to C# expressions. Updating the variables affects the markup attributes.

@page "/parameterex"
@rendermode InteractiveWebAssembly
<h3>ParameterEx</h3>
<div x-index="@xIndex" y-index="@yIndex" />
<button @onclick="UpdateParamters">Update</button>
@code {
    private int xIndex = 3;
    private int yIndex = 2;
    private void UpdateParamters()
    {
        xIndex = xIndex * 2;
        yIndex = yIndex * 2;
    }
}

Answer 3

in Blazor you use a lambda expression to pass the parameter(s) by closure.

<button @onclick="() => MyCallback(myparam1)">Click me</button>

note: the click event is captured by javascript and sent to the Blazor app via jsinterop, so no additional parameters are supported at the event level.