How to check if RenderFragment is empty?

RenderFragment is a delegate that renders a UI segment. So, it does not have an Empty state. It can be null, which is equivalent to empty in the sense that it will produce no rendered output. In the following example, see that the RenderFragments are in a null state or contain a value.

@if (childContent != null) 
{ 
    <p>@childContent</p> 
} 
else 
{ 
    <p>RenderFragment is null</p> 
} 
  
<button class="btn btn-primary" @onclick="OnButtonClick">Click</button> @*RenderFragment is null by default, click the button to update the RenderFragment*@ 
  
@code { 
    private string textContent = "Welcome to your new Blazor app."; 
    private RenderFragment childContent { get; set; } 
     
    private void OnButtonClick() 
    { 
        childContent = BuildRenderTree => BuildRenderTree.AddContent(1, textContent); 
    } 
}