实现效果如下：

代码如下：

                <el-dropdown trigger="click" @command="handleCommand" active-text-color="#606266"><span class="product-card">{{getCategoryName(categoryId)}}</span><el-dropdown-menu slot="dropdown"><template v-for="(item, index) in categories"><el-dropdown-itemclass="xlcdList":style="item.id == categoryId? 'color: #606266; background-color: #ecf5ff;': ''":key="index":command="item.id">{{ item.categoryName }}</el-dropdown-item></template></el-dropdown-menu></el-dropdown>

.el-dropdown-menu {background-color: #478068;
}.xlcdList {background-color: #478068;color: white;&:hover {// background-color: #478068;color: #606266;}
}