Question

当某人单击或打开下拉菜单时，我想做一个if语句

我已经尽力了，但是我是一个初学者

//Example on dropdown menu
<div class="dropdown">
  <button onclick="myFunction()" class="dropbtn">Dropdown</button>
  <div id="myDropdown" class="dropdown-content">
    <a href="#home">Home</a>
    <a href="#about">About</a>
    <a href="#contact">Contact</a>
  </div>
</div>

当您打开下拉菜单时，我想做一个if语句

Answer 1

如果我正确地理解了您，那么您希望在用户单击并打开下拉菜单时执行一些代码。因此，使用您的示例，可能是这样的：

add_action( 'template_redirect', 'role_based_redirect' );
function role_based_redirect() {
    if( is_page( array( 1488, 2413, 2379, 2265, 2396, 2370, 2366, 4600 ) ) ) { //check the list of "corporate" pages
        $user = wp_get_current_user();
        $valid_roles = [ 'administrator', 'corporate', 'editor' ];

        $the_roles = array_intersect( $valid_roles, $user->roles );

        // The current user does not have any of the 'valid' roles.
        if ( empty( $the_roles ) ) {
            wp_redirect( home_url( '/access-denied/' ) );
            exit;
        }
    }
}

Answer 2

似乎您正在使用bootstrap的下拉菜单。调整部分标记后，即可使用Dropdown Events。您需要在下拉列表中添加父div，然后在其上应用事件监听器。

$("#yourPersonalDropdownDivId").on("show.bs.dropdown", function() {
  alert("I'm  about to be shown, you will soon look at me !");
});
$("#yourPersonalDropdownDivId").on("shown.bs.dropdown", function() {
  alert("I'm shown, look at me !");
});
$("#yourPersonalDropdownDivId").on("hide.bs.dropdown", function() {
  alert("I'm about to hide, look at me while you still can !");
});
$("#yourPersonalDropdownDivId").on("shown.bs.dropdown", function() {
  alert("I'm hidden,you cannot look at me !");
});

<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"/>

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>


<div id="yourPersonalDropdownDivId">
  <div class="dropdown">
    <button class="btn dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</button>
    <div id="myDropdown" class="dropdown-menu dropdown-primary">
      <a href="#home">Home</a>
      <a href="#about">About</a>
      <a href="#contact">Contact</a>
    </div>
  </div>
</div>

然后您可以为条件设置布尔值或根据上下文执行代码。

当有人打开下拉菜单时如何制作if语句

2 个答案: