javascript - Now the page will only be triggered once when it is opened. How can it be triggered multiple times?

Question

if(document.getElementById('heldnav').offsetTop < (188+$('#img_img').height())){
    alert(1)
  $("#heldnav").addClass("normal_0");
}

Answer 1

Are you listening to some floating nav? You should first determine in what state you want to trigger this listener, such as a change in browser window size or something else, and then write your code in the corresponding event, such as resize, etc.

Answer 2

You should monitor scrolling, bind the scroll event to the element you want to monitor, and check the changes in real time

Answer 3

Add to the corresponding event to monitor

Answer 4

You need to add the corresponding scroll listening event to the floating object, and then do the judgment and processing in the method

Answer 5

Either add timer setInterval/setTimeout or add event function to achieve real-time monitoring

Answer 6

Either a timer or add an event listener. It depends on your needs. In short, it's impossible to just write a method and let it execute multiple times by itself, right?