Javascript window.onload不触发

Question

I am trying to write a javascript function that forces an element to have the style display = block. Currently it is being set to display = none by another piece of javascript.

I thought window.onload would solve the problem as the code is then not being overridden by the previous JS. The below code used to work and now the function just doesn't even fire.

Can anyone Help?

          window.onload =  function ()   // It sets the class of the unordered list when the page has been loaded.
            {
               ul.style.display = "block!important";   // Display all the child items
             }

Answer 1

You need to get your ul in the callback of the event listener because if you do it before, the DOM is not fully loaded.

document.addEventListener("DOMContentLoaded", function(event) { 
    var ul = document.getElementById("my-ul");

    ul.style.display = "block!important";
});

You can do it with JQuery if you want a more cross browser solution:

$(document).ready(function() {
    $('#my-ul').css('display', 'block!important');
});

You can do it in css:

#my-ul {
    display: block!important;
}

Your ul should be of the form for these solutions to work:

<ul id="my-ul">

Answer 2

You cannot use ul.style.display like that.

Use document. getElementsByTagName('ul').style.display = "block !important" document. getElementsByTagName('ul').style.display = "block !important"

Answer 3

window.onload = function() ... is defining a function. Just call the function right after you close it with window.onload(); Worked for me after many hours