1. Bind inline style setting why the background picture is not displayed? 
 the same DIV can be displayed by setting the background image through ID in CSS 
2.
  <div id="test" 
  :style="{ backgroundImage:"url("+"./assets/logo.png"+")", backgroundSize:"cover",
  backgroundPosition:"center center"}" ></div>
  
    -sharptest {
    width: 700px;
    height: 500px;
    margin: 0 auto;
    border: 1px black solid;
    background: url("./assets/logo.png");
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center center;
    }
 3. As shown in figure 
  
 and I found that the image path set in CSS is rendered in the browser as 
 background: url (/ img/logo.82b9c7a5.png); 
 so 
