OutsideHandleContainer.razor

@using Microsoft.JSInterop;
@inject Microsoft.JSInterop.IJSRuntime JSRuntime;
<div id="@Id">
    @ChildContent
</div>
@code{
    [Parameter]
    public Action OnClickOutside { get; set; }
    private string Id { get; set; } = Guid.NewGuid ().ToString ();
    [Parameter]
    public RenderFragment ChildContent { get; set; }
    protected override Task OnInitializedAsync () {
        JSRuntime.InvokeAsync<object> ("outsideClickHandler.addEvent", Id, DotNetObjectReference.Create(this));
        return base.OnInitializedAsync ();
    }
    [JSInvokable]
    public void InvokeClickOutside () {
        OnClickOutside?.Invoke ();
    }
}