Is EventCallBack possible in Blazored Modal?

[nagtilaklaxman]

Is EventCallBack possible in Blazored Modal?
I want to pass some event information to parent component without closing the model.

[larsk2009]

That should be possible, see the following code snippets. I used the index.razor page from the examples for this as a start.

index.razor

@page "/"

<h1>Blazored Modal Sample</h1>

<hr class="mb-5" />

<p>
    This is an example of using Blazored Modal in its most simplistic form.
</p>

<div class="card mb-4">
    <div class="card-body">
        <p class="card-text">
            <code>
                @("Modal.Show<Confirm>(\"Welcome to Blazored Modal\", options);")
            </code>
        </p>
    </div>
</div>

<button @onclick="ShowModal" class="btn btn-primary">Show Modal</button>

@code {

    [CascadingParameter] public IModalService Modal { get; set; }

    void ShowModal()
    {
        var parameters = new ModalParameters();
        parameters.Add(nameof(Confirm.Callback), EventCallback.Factory.Create<string>(this, CallbackFromModal));
        Modal.Show<Confirm>("Welcome to Blazored Modal", parameters);
    }

    private void CallbackFromModal(string value)
    {
        Console.WriteLine(value);
    }

}

The component:
Confirm.razor

<div>
    <p>Please click one of the buttons below to close or cancel the modal.</p>

    <button @onclick="UseCallback" class="btn btn-danger">Callback</button>
    <button @onclick="Close" class="btn btn-primary">Close</button>
    <button @onclick="Cancel" class="btn btn-secondary">Cancel</button>
</div>

@code {

    [CascadingParameter] BlazoredModalInstance BlazoredModal { get; set; }

    [Parameter]
    public EventCallback<string> Callback { get; set; }

    async Task Close() => await BlazoredModal.CloseAsync(ModalResult.Ok(true));
    async Task Cancel() => await BlazoredModal.CancelAsync();

    async Task UseCallback() => await Callback.InvokeAsync("test 1 2 3");
}

If you place a breakpoint in the CallbackFromModal function on the Index.razor page, you will see the function getting called from the callback, and the modal staying up.

Hopefully this answers your question.