Does Tempdata lose property when using Response.Redirect?

Question

I have the following code on the pages that, to be accessed, it is necessary to log in:

if (Session["Login"] == null)
{
    TempData["msg"] = "É necessário realizar o login para acessar esta página!";
    Response.Redirect("/Login/Index");
}

This TempData["msg"] is as follows on the login screen:

@if (TempData["msg"] != null)
{
    <div class="alert alert-danger">
       @TempData["msg"]
    </div>
}

However the message is not appearing, as if the TempData is undoing itself. What do I have to do to get the message passed to the login screen?

Answer 1

Use the ViewBag for it exists until the end of the execution of response.

On the controller:

if (Session["Login"] == null)
{
    ViewBag.msg = "É necessário realizar o login para acessar esta página!";
    Response.Redirect("/Login/Index");
}

In view:

@if (TempData["msg"] != null)
{
    <div class="alert alert-danger">
       @ViewBag.msg
    </div>
}