Detect F5 being pressed and Refresh

问题

I have a webform and i want to detect if F5 button was pressed or if the page was refreshed. I know about postback but it is not what i'm looking for. I have a gridview that loads in a modal popup when a button is clicked and a parameter's value is set for the gridview. When refresh is hit and if the modal popup button was previously clicked the modal popup is visible right after refresh. I want to detect if the page is refreshed to prevent this. any ideas? I thought to try Override but I'm not exactly sure how to use it. I tried Control.ModifierKeys but I don't have access to ModifierKeys.

回答1:

Pressing F5 or physically clicking the browser refresh behaves similarly to navigating away from the page. This is captured in the event window.onunload. Try the snippet example below:

window.onbeforeunload = function (evt) {
  var message = 'Are you sure you want to leave?';
  if (typeof evt == 'undefined') {
    evt = window.event;
  }
  if (evt) {
    evt.returnValue = message;
  }
  return message;
}

This will capture the refresh and allow you to do something or prompt the user.

回答2:

Reemember that hotkeys are processed in the client side in the browser. The easiest way to implement this is through javascript.

Look at the following link:

http://snippets.dzone.com/posts/show/3552

来源：https://stackoverflow.com/questions/908075/detect-f5-being-pressed-and-refresh