When the value of select cannot be obtained normally in the layer pop-up layer, the method can be used

/**
  * layer-drop-down box binding change event
  *
  */
  $(document).on('change', '#ruleType', function() {
	var val = $ (this) .val ();
	$("#hideRuleTypeId").val(val);// Assign the selected value to the hidden box
   });
	 
  /**
    * layer-add-add binding click event
    *
    */
  $(document).on('click', '#addRuleOrTransform', function() {
	alert($("#hideRuleTypeId").val());// Get the value in the hidden box, which is the value selected in the drop-down box
  });