Web-Development-with-Blazor-Second-Edition/Chapter12/MyBlog/Components/Pages/CounterWithParameterAndEvent.razor

@page "/counterwithparameter"
<h1>Counter</h1>
<p>Current count: @CurrentCount</p>
<button class="btn btn-primary" @onclick="IncrementCount">Click me</button>
@code {
    [Parameter]
    public int IncrementAmount { get; set; } = 1;
    [Parameter]
    public int CurrentCount { get; set; } = 0;
    //private void IncrementCount()
    //{
    //    CurrentCount+=IncrementAmount;
    //}

    [Parameter]
    public EventCallback<int> CurrentCountChanged { get; set; }
    private void IncrementCount()
    {
        CurrentCount += IncrementAmount;
        CurrentCountChanged.InvokeAsync(CurrentCount);
    }
}