带内部图标的Javascript onclick动作问题

Question

当我在锚标记中放置一个图标并使用锚标记创建一个onClick动作以下拉div时，该下拉菜单将正常工作，但是当我在图标周围单击并单击图标时，该下拉菜单将无法正常工作

但是，当我在范围内和锚标记中放置img图标时。

当我点击图标而不是点击图标时如何进行下拉？

我的HTML，CSS和JS代码：

function myFunction() {
  document.getElementById("myDropdown").classList.toggle("show");
}


window.onclick = function(event) {
  if (!event.target.matches('.dropbtn')) {
    var dropdowns = document.getElementsByClassName("dropdown-content");
    var i;
    for (i = 0; i < dropdowns.length; i++) {
      var openDropdown = dropdowns[i];
      if (openDropdown.classList.contains('show')) {
        openDropdown.classList.remove('show');
      }
    }
  }
}

.dropbtn {
  padding: 10px;
  font-size: 16px;
  cursor: pointer;
}

.dropbtn:hover,
.dropbtn:focus {
  background-color: inhert;
}

.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f1f1f1;
  min-width: 160px;
  overflow: auto;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  z-index: 1;
  margin-top: 5px;
  opacity: 1;
  visibility: visible;
  background: #fff none repeat scroll 0 0;
  box-shadow: 0 3px 4px -1px rgba(0, 0, 0, 0.2);
  margin-top: 35px;
  padding: 20px;
  position: absolute;
  right: 0;
  top: 100%;
  width: 290px;
  z-index: 9999;
}

.dropdown-content h2 {
  font-size: 14px;
  margin: 0;
}

.dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
}

.dropdown a:hover {
  background-color: inherit;
}

.show {
  display: block;
}

<div class="mini-cart-box mini-cart10">
  <a onclick="myFunction()" class="dropbtn" href="#">
    <span><img src="~/Front/images/theme/wishfi.svg.svg" alt="" width="33px" height="35px" /></span>
    <span id="catval" class="mini-cart-number"></span>
  </a>
  <div id="myDropdown" class="dropdown-content">
  </div>
</div>