Program.cs

varbuilder=WebApplication.CreateBuilder();
builder.Services.AddControllersWithViews();
builder.Services.AddRazorPages();

varapp=builder.Build();
app.UseMiddleware<GreeterMiddleware>();
app.MapRazorPages();
app.Run();

publicclassGreeterMiddleware
{
RequestDelegate_next;

readonlyLinkGenerator_linkGenerator;

publicGreeterMiddleware(RequestDelegatenext,LinkGeneratorlinkGenerator)
{
_next=next;
_linkGenerator=linkGenerator;
}

publicasyncTaskInvokeAsync(HttpContexthttpContext)
{
EndpointendPoint=httpContext.GetEndpoint();

if(endPoint.DisplayName=="/about")
{
httpContext.Items.Add("GreetingFromMiddleWare","Hello world from GreetingMiddleware");
}

await_next.Invoke(httpContext);
}
}