Doing a refresh after certain action in asp.net seems to make them happen again even when that action doesn't make sense (think double delete). The web way to deal with this situation is to redirect after a post to get a clean version of the page that can be refreshed without reposting an action to the webserver. How can I do this with ASP.NET
I have a feeling there is a deeper problem I'm not getting but here goes. In your postback event:
// the post handling logic, e.g. the click event code
Response.Redirect(Request.RawUrl);
Use Server.Transfer method.
The Server.Transfer method has a second parameter—"preserveForm". If you set this to True, using a statement such as Server.Transfer("WebForm2.aspx", True), the existing query string and any form variables will still be available to the page you are transferring to.
来源：https://stackoverflow.com/questions/331277/how-do-i-use-the-post-redirect-get-a-k-a-redirect-after-post-with-asp-net