It seems you're running into confusion regarding how TempData behaves after it's read, especially in the context of redirects. Normally, TempData is designed to persist until it's read and can be used to pass data between actions. However, in some cases, especially with RedirectToAction, TempData doesn’t clear automatically on reading unless explicitly removed.
In your scenario, after reading TempData, it should ideally be cleared, but you’ve observed that you still need to call TempData.Remove(). This is because TempData persists across RedirectToAction, ensuring that the data survives the redirect, which might explain why you still see the need to remove it manually.
To clarify:
TempData survives redirects, allowing you to access it in the next action. If you don’t need it to persist across multiple actions after a redirect, you’ll have to remove it manually using TempData.Remove(). If you prefer something more persistent, like session-based storage, Session might be a better choice, especially when you need to retain data across multiple requests without worrying about clearing it immediately.
Let me know if that helps clarify things!