TempData is null after redirection - asp.net-core-mvc

Question

I want use TempData to pass messages between Test1 and Test2 actions but when I read tempdata's key on Test2's action the value on TempData key is null. I read the documentation about TempData on MDSN this is what it say:
Represents a set of data that persists only from one request to the
next.
My code is that:
public class TestController : Controller
{
public const string TEMP_DATA_KEY = "TEST";
public IActionResult Test1()
{
TempData[TEMP_DATA_KEY] = "ciao";
return RedirectToAction(nameof(Test2));
}
public IActionResult Test2()
{
TempData.TryGetValue(TEMP_DATA_KEY, out object saluto);
return View();
}
}
What is wrong, Test1 is first request Test2 is next request why TempData is null?
Thank you regards

Answer 1

In your controller update the Test2 Action as noted below:
public const string TEMP_DATA_KEY = "TEST";
public IActionResult Test1()
{
TempData[TEMP_DATA_KEY] = "ciao";
return RedirectToAction(nameof(Test2));
}
public IActionResult Test2()
{
TempData.TryGetValue(TEMP_DATA_KEY, out object saluto);
return View(saluto);
}
Update your View (Test2.cshtml) as shown below.
#model string
#{
ViewData["Title"] = "Test2";
}
<h1>#Model</h1>
This wil show the value you've added in Test1 into your TempData in the h1 tag on the Test2 View.