为什么 MDCSelect:change 不适用于材料设计的 javascript

Lea*_*ner 7 html javascript jquery material-design mdc-components

为什么MDCSelect:change在附加所有选项之前调用它时不起作用

MDCSelect:change当我在附加列表后放置它时正在工作,但UI 看起来不太好。

问题:如何MDCSelect:change在不损害 ui 外观的情况下工作。

当我洗牌那两行的代码时,它工作得很好

$('#select_dropdown').html(usersStr);

initializeSelect();
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select UI当您在任何地方或简单地单击外部时,上面的代码看起来不太好

为了更好地查看,我在这里创建了 codepen:https ://codepen.io/eabangalore/pen/poNmBpm ? editors = 1010

$('#select_dropdown').html(usersStr);

initializeSelect();
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var selectBoxMap = {};
function initializeSelect(){
       var mdcSelectList = document.querySelectorAll(' .mdc-select');
        if(mdcSelectList){
            [].forEach.call(mdcSelectList,function(el){
                var select = new mdc.select.MDCSelect(el);
                el.setAttribute('ripple-attached', true);
                var dropDownId = $(el).find('ul.mdc-list').attr('id');
                selectBoxMap[dropDownId] = select;
            });
        }

}


$(async function(){

  var results = await $.get('https://jsonplaceholder.typicode.com/users');
var usersStr = '';
for(var i = 0; i < results.length; i++){
    var item = results[i];
           usersStr += `<li class="mdc-list-item" data-id="${item.id}" role="option">
                              <span class="mdc-list-item__ripple"></span>
                              <span class="mdc-list-item__text" data-id="${item.id}">
                                  ${item.name}
                              </span>
                          </li>`
}

initializeSelect();

$('#select_dropdown').html(usersStr);

     for(var key in selectBoxMap){
            if(selectBoxMap[key]){
              selectBoxMap[key].listen('MDCSelect:change', (e) => {
                  alert('dropdown changed');
              });
            }
        }

});
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我仍在寻找解决方案,请帮助我提前谢谢!!

ash*_*nka 1

我从这个链接得到了这个想法

var selectBoxMap = {};
function initializeSelect(){
       var mdcSelectList = document.querySelectorAll(' .mdc-select');
        if(mdcSelectList){
            [].forEach.call(mdcSelectList,function(el){
                var select = new mdc.select.MDCSelect(el);
                el.setAttribute('ripple-attached', true);
                var dropDownId = $(el).find('ul.mdc-list').attr('id');
                selectBoxMap[dropDownId] = select;
            });
        }

}


$(async function(){

  var results = await $.get('https://jsonplaceholder.typicode.com/users');
var usersStr = '';
for(var i = 0; i < results.length; i++){
    var item = results[i];
           usersStr = `<li class="mdc-list-item" aria-selected="false" data-value=" ${item.name}" role="option">
                        <span class="mdc-list-item__ripple"></span>
                        <span class="mdc-list-item__text">
                          ${item.name}
                        </span>
                    </li>`;
                $('#select_dropdown').append(usersStr);
}

initializeSelect();



     for(var key in selectBoxMap){
            if(selectBoxMap[key]){
              selectBoxMap[key].listen('MDCSelect:change', (e) => {
                  alert('dropdown changed');
              });
            }
        }

});
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<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<head>
  <link href="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.css" rel="stylesheet">
 <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
 <script src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"></script>

</head>


<!-- select dropdown -->

 <div class="mdc-select mdc-select--filled demo-width-class">
         <div class="mdc-select__anchor" role="button" aria-haspopup="listbox" aria-expanded="false">
                      <span class="mdc-select__ripple"></span>
                      <span class="mdc-floating-label">Status</span>
                      <span class="mdc-select__selected-text-container">
                        <span id="" class="mdc-select__selected-text"></span>
                      </span>
                      <span class="mdc-select__dropdown-icon">
                          <span class="mdc-select__dropdown-icon-inactive material-icons">arrow_drop_down</span>
                          <span class="mdc-select__dropdown-icon-active material-icons">arrow_drop_up</span>
                      </span>
                      <span class="mdc-line-ripple"></span>
                    </div>
                  
                    <div class="mdc-select__menu mdc-menu mdc-menu-surface mdc-menu-surface--fullwidth">
                      <ul class="mdc-list" id="select_dropdown"  role="listbox" aria-label="listbox">
          
                      </ul>
          </div>
   </div>
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