选择多个下拉列值时启用/禁用按钮

我一直在尝试使用jQuery代码在选择所有html选择下拉列表时启用按钮，或者如果没有选择单个按钮则尝试禁用按钮。

这是我到目前为止尝试过但我的代码无法正常工作。 有什么建议吗？

$(function() { $('.picker').on('change', function() { var SelectList = $('.picker'); //Here i'll find how many dropdown are present for (var i = 0; i < SelectList.length; i++) { //Here i need to check each dropdown value whether it selected or not if (SelectList[i].val() != "") { //If all dropdown is selected then Enable button $("#Testing").attr("disabled", true); } else { //Disable button if any dropdown is not selected $("#Testing").attr("disabled", false); } } }); }); 

  
  Select A B C  
 
  Select A B C  
 
  Select A B C  
 
  Select A B C  
 
  Select A B C  
 
   

Answer 1

无需循环 – 我也会触发更改onload以在（重新）加载时禁用：

 $(function() { $('.picker').on('change', function() { var $sels = $('.picker option:selected[value=""]'); $("#Testing").attr("disabled", $sels.length > 0); }).change(); }); 

  
  Select A B C  
 
  Select A B C  
 
  Select A B C  
 
  Select A B C  
 
  Select A B C  
 
   

Answer 2

使用下面的代码SelectList [i] .value而不是SelectList [i] .val（）

  $(function () { $('.picker').on('change', function () { var SelectList = $('.picker'); //Here i'll find how many dropdown are present for (var i = 0; i < SelectList.length ; i++) { //Here i need to check each dropdown value whether it selected or not if (SelectList[i].value != "") { //If all dropdown is selected then Enable button $("#Testing").attr("disabled", true); } else { //Disable button if any dropdown is not selected $("#Testing").attr("disabled", false); } } }); });