KendoDropDownList TabIndex没有生效

我正在使用KendoDropDownList小部件，并且在标记中，select元素在其上设置了tabindex="600"。但它没有生效。我确实在提交给客户的最终标记中看到它。KendoDropDownList TabIndex没有生效

<span style="" title="" class="k-widget k-dropdown k-header form-control" 
    unselectable="on" role="listbox" aria-haspopup="true" 
    aria-expanded="false" tabindex="610" 
    aria-owns="PropertyAddress_State_listbox" 
    aria-disabled="false" aria-readonly="false" aria-busy="false"> 

    <span class="k-dropdown-wrap k-state-default" unselectable="on"> 
     <span class="k-input" unselectable="on">CA</span> 
     <span class="k-select" unselectable="on"> 
      <span class="k-icon k-i-arrow-s" unselectable="on">select</span 
     </span> 
    </span> 
    <select name="PropertyAddress.State" id="PropertyAddress_State" 
     data-role="dropdownlist" class="form-control" style="display: none;"> 
     <option value="AK">AK</option> 
     <option value="AL">AL</option> 
     . 
     . 
    </select> 
</span>

但是制表符不会像正常的select元素那样触发下拉菜单。任何想法如何以及如果它可以工作？

来源

2015-10-15 Brian Mains