条纹效果

<div class="progress">
  <div class="progress-bar progress-bar-success progress-bar-striped" role="progressbar" aria-valuenow="40" aria-valuemin="0" aria-valuemax="100" style="width: 40%">
    <span class="sr-only">40% Complete (success)</span>
  </div>
</div>
<div class="progress">
  <div class="progress-bar progress-bar-info progress-bar-striped" role="progressbar" aria-valuenow="20" aria-valuemin="0" aria-valuemax="100" style="width: 20%">
    <span class="sr-only">20% Complete</span>
  </div>
</div>
<div class="progress">
  <div class="progress-bar progress-bar-warning progress-bar-striped" role="progressbar" aria-valuenow="60" aria-valuemin="0" aria-valuemax="100" style="width: 60%">
    <span class="sr-only">60% Complete (warning)</span>
  </div>
</div>
<div class="progress">
  <div class="progress-bar progress-bar-danger progress-bar-striped" role="progressbar" aria-valuenow="80" aria-valuemin="0" aria-valuemax="100" style="width: 80%">
    <span class="sr-only">80% Complete (danger)</span>
  </div>
</div>