如何在blazor中从EventCallback中获取返回值？

public delegate Task MyDelegate(string arg);

public class MyComponent : ComponentBase
{
    [Parameter]
    public MyDelegate MyEvent { get; set; }

    private async Task HandleEvent()
    {
        string result = await MyEvent.Invoke("argument");
        // 处理返回值
    }
}

public class MyComponent : ComponentBase
{
    [Parameter]
    public EventCallback<string> MyEvent { get; set; }

    private async Task HandleEvent()
    {
        var tcs = new TaskCompletionSource<string>();
        await MyEvent.InvokeAsync("argument", tcs.SetResult);
        string result = await tcs.Task;
        // 处理返回值
    }
}