c# - Does page reload ever cause post?

Question

Quick question, I have tried figuring this out myself, but the use of Session Variables can be confusing when trying to figure out why or how a page is reloading and doing/not doing what it is supposed to do.

Does a page reload (with JavaScript, f5, ctrl+f5, browser reload button, etc) ever, under any (non-scripted) circumstance cause a form repost?

(This pertains to using IfPost branches within C# code like the example code below):

if(IsPost)
{
    //stuff that only executes if the previous request was a post.
}

I just kind of need to know what to expect here so I can properly diagnose my session state problems.

Thanks for any help!

(Also, sorry if I am oversimplifying this question. I realize that it 'may' be more complicated than a simple answer can provide).

******UPDATE********** Also, I looked for copies of this question here, on StackOverflow, but I didn't see anything, so if this is a duplicate question, I apologize.

Both of the answers here are good answers. I accepted the answer that also offered a solution to my question, and while PRG is not the 'only' way to do it, it seems like it may be the best. It also seems a growing way to handle client-side user-friendliness, and imho, seems like it would be a great habit to get into.

Thanks for showing me that!

Answer 1

Yes. If the page was loaded using POST data this will occur. To prevent this you need to implement the POST/REDIRECT/GET pattern.

Post/Redirect/Get (PRG) is a web development design pattern that prevents some duplicate form submissions, creating a more intuitive interface for user agents (users). PRG supports bookmarks and the refresh button in a predictable way that does not create duplicate form submissions.