二維碼掃描的樣式總結

我想大家都用過掃碼插件，也想像微信和支付寶那樣。但是有些插件是可以自定義樣式的，但是有些則不行了。現在開發的app中有用到掃碼的插件，但是默認的樣式很醜，所以就想着能夠能夠實現像微信和支付寶那樣的樣式。
代碼如下：
html

<div class="scan"></div>

css

.scan {
  width: 150px;
  height: 150px;
  margin: 30px auto;
  position: relative;
  background: linear-gradient(to left, #108EE9, #108EE9) left top no-repeat, linear-gradient(to bottom, #108EE9, #108EE9) left top no-repeat, linear-gradient(to left, #108EE9, #108EE9) right top no-repeat, linear-gradient(to bottom, #108EE9, #108EE9) right top no-repeat, linear-gradient(to left, #108EE9, #108EE9) left bottom no-repeat, linear-gradient(to bottom, #108EE9, #108EE9) left bottom no-repeat, linear-gradient(to left, #108EE9, #108EE9) right bottom no-repeat, linear-gradient(to left, #108EE9, #108EE9) right bottom no-repeat;
  background-size: 3px 20px, 20px 3px, 3px 20px, 20px 3px;
}

.scan::after {
  content: '';
  width: 140px;
  border: 1px solid #BBE2FF;
  position: absolute;
  left: 5px;
  top: 2px;
  animation: myfirst 4s infinite;
}
@keyframes myfirst {
  from {
    top: 2px;
  }
  to {
    top: 144px;
  }
}

最終的效果如圖：

background: linear-gradient(to left, #108EE9, #108EE9) left top no-repeat, linear-gradient(to bottom, #108EE9, #108EE9) left top no-repeat, linear-gradient(to left, #108EE9, #108EE9) right top no-repeat, linear-gradient(to bottom, #108EE9, #108EE9) right top no-repeat, linear-gradient(to left, #108EE9, #108EE9) left bottom no-repeat, linear-gradient(to bottom, #108EE9, #108EE9) left bottom no-repeat, linear-gradient(to left, #108EE9, #108EE9) right bottom no-repeat, linear-gradient(to left, #108EE9, #108EE9) right bottom no-repeat;
background-size: 3px 20px, 20px 3px, 3px 20px, 20px 3px;

這兩行代碼是實現四個藍色角的關鍵，也是其中不好懂的地方。
如果掃描二維碼插件需要自定義樣式的話，那就用起來吧。