aspnetcore/src/Components/test/testassets/TestContentPackage/Counter.razor

<p>Increment amount: @IncrementAmount</p>
<p>Interactive: <span id="is-interactive-@IdSuffix">@_isInteractive</span></p>
<p>Current count: <span id="count-@IdSuffix">@_currentCount</span></p>

<button id="increment-@IdSuffix" @onclick="IncrementCount">Click me</button>

@code {
    private int _currentCount = 0;
    private bool _isInteractive = false;

    [Parameter, EditorRequired]
    public int IncrementAmount { get; set; }

    [Parameter, EditorRequired]
    public string IdSuffix { get; set; }

    private void IncrementCount()
    {
        _currentCount += IncrementAmount;
    }

    protected override void OnAfterRender(bool firstRender)
    {
        if (firstRender)
        {
            _isInteractive = true;
            StateHasChanged();
        }
    }
}