图像上方有角度的色带css

Question

我正在尝试在图像上创建一个成角度的带状色带。如下面的屏幕快照所示，我要在已售商品上显示“已售”功能区

下面是我使用引导程序4在其中显示项目的代码笔的链接。到目前为止，我已经能够显示SOLD功能区，但是不知何故它出现在屏幕顶部而不是图像/项目。如果有人指导我在已售商品上显示“已售”功能区，那将是很大的帮助。据您所知，我对CSS的了解很少。

Codepen：https://codepen.io/stephen0roper/pen/pQbjbq

这是我创建的用于显示功能区的示例代码：

/* The ribbons */

.corner-ribbon {
  font-weight: bold;
  width: 200px;
  background: #e43;
  position: absolute;
  top: 25px;
  left: -50px;
  text-align: center;
  line-height: 100px;
  letter-spacing: 1px;
  color: #f0f0f0;
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
}


/* Custom styles */

.corner-ribbon.sticky {
  position: fixed;
}

.corner-ribbon.shadow {
  box-shadow: 0 0 3px rgba(0, 0, 0, .3);
}


/* Different positions */

.corner-ribbon.top-left {
  top: -10px;
  left: -103px;
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
  background-color: red;
  width: 256px;
  height: 75px;
}

Answer 1

因为您使用position: fixed;而不是.corner-ribbon的绝对值。 .card类还需要一个overflow: hidden;。这是工作示例：

/* The ribbons */
.corner-ribbon{
  font-weight: bold;
  width: 200px;
  background: #e43;
  position: absolute;
  top: 25px;
  left: -50px;
  text-align: center;
  line-height: 100px;
  letter-spacing: 1px;
  color: #f0f0f0;
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
}

.card {
  overflow: hidden;
}

.corner-ribbon.shadow{
  box-shadow: 0 0 3px rgba(0,0,0,.3);
}

/* Different positions */

.corner-ribbon.top-left{
    top: -10px;
    left: -103px;
    transform: rotate(-45deg);
    -webkit-transform: rotate(-45deg);
    background-color: red;
    width: 256px;
    height: 75px;
}

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet"/>
  <header>
      <div class="collapse bg-dark" id="navbarHeader">
        <div class="container">
          <div class="row">
            <div class="col-sm-8 col-md-7 py-4">
              <h4 class="text-white">About</h4>
              <p class="text-muted">Add some information about the album below, the author, or any other background context. Make it a few sentences long so folks can pick up some informative tidbits. Then, link them off to some social networking sites or contact information.</p>
            </div>
            <div class="col-sm-4 offset-md-1 py-4">
              <h4 class="text-white">Contact</h4>
              <ul class="list-unstyled">
                <li><a href="#" class="text-white">Follow on Twitter</a></li>
                <li><a href="#" class="text-white">Like on Facebook</a></li>
                <li><a href="#" class="text-white">Email me</a></li>
              </ul>
            </div>
          </div>
        </div>
      </div>
      <div class="navbar navbar-dark bg-dark shadow-sm">
        <div class="container d-flex justify-content-between">
          <a href="#" class="navbar-brand d-flex align-items-center">
            <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="mr-2"><path d="M23 19a2 2 0 0 1-2 2H3a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h4l2-3h6l2 3h4a2 2 0 0 1 2 2z"></path><circle cx="12" cy="13" r="4"></circle></svg>
            <strong>Album</strong>
          </a>
          <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarHeader" aria-controls="navbarHeader" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
          </button>
        </div>
      </div>
    </header>

    <main role="main">
      <div class="album py-5 bg-light">
        <div class="container">

          <div class="row">
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <div class="corner-ribbon top-left sticky shadow">SOLD</div>
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item1" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item2" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item3" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>

            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item4" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item5" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item6" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>

            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item7" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item8" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
            <div class="col-md-4">
              <div class="card mb-4 shadow-sm">
                <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item9" alt="Card image cap">
                <div class="card-body">
                  <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
                  <div class="d-flex justify-content-between align-items-center">
                    <div class="btn-group">
                      <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                      <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                    </div>
                    <small class="text-muted">9 mins</small>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </div>
      </div>

    </main>

    <footer class="text-muted">
      <div class="container">
        <p class="float-right">
          <a href="#">Back to top</a>
        </p>
        <p>Album example is &copy; Bootstrap, but please download and customize it for yourself!</p>
        <p>New to Bootstrap? <a href="../../">Visit the homepage</a> or read our <a href="../../getting-started/">getting started guide</a>.</p>
      </div>
    </footer>

Answer 2

删除.corner-ribbon.sticky {position: fixed;}

您希望每个角带都绝对定位，这是根据它们各自最近的定位祖先计算得出的。这就是绝对定位的作用。

position: fixed将根据视口计算其位置，这不是您想要的。

添加.card {overflow: hidden;}

/* The ribbons */

.corner-ribbon {
  font-weight: bold;
  width: 200px;
  background: #e43;
  position: absolute;
  top: 25px;
  left: -50px;
  text-align: center;
  line-height: 100px;
  letter-spacing: 1px;
  color: #f0f0f0;
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
}


/* Custom styles */

.corner-ribbon.shadow {
  box-shadow: 0 0 3px rgba(0, 0, 0, .3);
}


/* Different positions */

.corner-ribbon.top-left {
  top: -10px;
  left: -103px;
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
  background-color: red;
  width: 256px;
  height: 75px;
}

.card {
  overflow: hidden;
}

<link href="https://getbootstrap.com/docs/4.1/dist/css/bootstrap.min.css" rel="stylesheet"/>
<main role="main">
  <div class="album py-5 bg-light">
    <div class="container">

      <div class="row">
        <div class="col-md-4">
          <div class="card mb-4 shadow-sm">
            <div class="corner-ribbon top-left sticky shadow">SOLD</div>
            <img class="card-img-top" src="http://dummyimage.com/400x400/000/fff?text=Item1" alt="Card image cap">
            <div class="card-body">
              <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>
              <div class="d-flex justify-content-between align-items-center">
                <div class="btn-group">
                  <button type="button" class="btn btn-sm btn-outline-secondary">View</button>
                  <button type="button" class="btn btn-sm btn-outline-secondary">Edit</button>
                </div>
                <small class="text-muted">9 mins</small>
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>
  </div>
</main>

Answer 3

您好，这是您为图像设置色带角的解决方案：

CSS：

.corner {
 width: 0; 
height: 0; 
border-top: 120px solid #ffc107;
border-right: 120px solid transparent;
position:absolute;
left:27px;
top:12px;
}
.corner span {
 position:relative;
 top: -99px;
 left: 31px;
 text-align: center;
 font-size: 13px;
 font-family: arial;
 transform: rotate(-45deg);
 font-weight:600;
 display:block;
 }

HTML：

 <div class="row">
  <div class="col-sm-12">
    <div class="col-sm-3">
      <div class="thumbnail">
        <div class="corner"><span>20% Special Offer</span></div>
         <a href="#">
          <img style="height:200px;width:250px;" src="SAMPLE.PNG " > 
       </a> 
      <div class="caption text-center">
       <h5 class="cus"> sample ji </h5>
      </div>
    </div>
 </div>
 </div>

Answer 4

您必须将position:relative;添加到.corner-ribbon父级：.card

.corner-ribbon也必须位于position:absolute;而非position:fixed;

要使用CSS绘制三角形，请阅读How do CSS triangles work?