使用Bootstrap 4，如何在移动/平板电脑视图中折叠边栏

Question

I was hoping to get some help on creating a collapsible sidebar that is expanded on lg and higher views, but is collapsed with a (now visible) button to expand on tablet and mobile views (md or smaller).

So break it down: -How would I make my sidebar collapsible on mobile/tablet views? (xs, md, lg) -It need to be expanded in desktop views (lg, xl) -And have a toggle button that's hidden in large desktop views, but displays in small mobile/tablet views. -Do I need to write some custom JS? -Linked here are the BS4 Docs for Collapse, but I didn't understand how this would do what I need ( https://getbootstrap.com/docs/4.0/components/collapse/#options ). Maybe a JS person could help.

Thank you for your help!

//The Button
<h4 class="mb-3"><span class="text-muted">Search Filters</span>
    <button class="navbar-toggler border"
    type="button"
    data-toggle="collapse"
    data-target="#sidebar"
    aria-expanded="false"
    aria-label="Toggle filters">
      <span><i class="fas fa-filter"></i></span>
    </button>
 </h4>




//The Sidebar    
  <ul id="sidebar" class="list-group mb-3">
    <li class="list-group-item d-flex justify-content-between lh-condensed">
      <div>
        <h6 class="my-0">Header</h6>
        <div class="input-group mb-3">
          <ul>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
          </ul>
        </div>
    </li>
    <li class="list-group-item d-flex justify-content-between lh-condensed">
      <div>
        <h6 class="my-0">Header</h6>
        <div class="input-group mb-3">
          <ul>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
          </ul>
        </div>
    </li>
    <li class="list-group-item d-flex justify-content-between lh-condensed">
      <div>
        <h6 class="my-0">Header</h6>
        <div class="input-group mb-3">
          <ul>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
            <li><input type="checkbox" aria-label="Checkbox"> Checkbox List Item </li>
          </ul>
        </div>
    </li>
  </ul>
  </div>

Answer 1

Well, with some help on other websites I figured out the solution. The guys at the Slack Bootstrap Help Channel were kind enough to point me in the right direction by linking a StackOverflow thread .

Using that link along with the Collapse Documentation at Bootstrap I was able to figure it out. Below is the answer...

// Used jQuery to create the new logic:

  if ($(window).width() < 922) {
    $('#sidebar').collapse({
      toggle: false
    });
  } else {
    $('#sidebar').collapse({
      toggle: true
    });
  }


// Also, needed to add the .collapse class to the UL:

  <ul id="sidebar" class="collapse list-group mb-3">
      ....
  </ul>

I hope this helps others!

Answer 2

No need to use JS, use Bootstrap classes: https://getbootstrap.com/docs/4.1/utilities/display/#hiding-elements

You could do this:

//The Button: The class d-lg-none will hide the filters for large size (ie: it'll be visible on xs-s-md sizes only)

<h4 class="d-lg-none mb-3"><span class="text-muted">Search Filters</span>
 <button class="navbar-toggler border"
 type="button"
 data-toggle="collapse"
 data-target="#sidebar"
 aria-expanded="false"
 aria-label="Toggle filters">
  <span><i class="fas fa-filter"></i></span>
</button>
 </h4>



//The Sidebar : "d-none d-lg-block" will display the sidebar only on large size

  <ul id="sidebar" class="d-none d-lg-block list-group mb-3">
....
</ul>