如何在jQuery中下拉列表更改时更改字体颜色？

Question

我试图在下拉框中更改文本的颜色。紧急，重要和正常。紧急应为红色，重要橙色和正常为绿色。我创建了以下JavaScript但另一个警报在示例警报旁边不起作用。颜色也不会改变。

        var d = NWF$('#' + jsPriority + ' option:selected').val();
       //alert(d);
        switch (d)
  {
            case("Urgent - Immediate Attention or Response Required within 2 days"):
                 alert(d);
                 //$(this).find('option:selected').css('color', 'red');
                 NWF$('#'+jsPriority).find('option:selected').css('color', 'red');
                 break;
            //case d.startsWith("Urgent"):            
            //break;
            case ("Important - High Attention or Response Required within 7 days"): 
                NWF$('#'+jsPriority).find('option:selected').css('color', 'orange');                
                break;
            case ("Normal - Review or Response Required within 14 days"): 
                //alert(d);
                NWF$('#'+jsPriority).find('option:selected').css('color', 'green');
                break;            
        }

Answer 1

我终于开始工作了。这是jquery代码的工作版本。

// coloring priority
NWF$(document).ready(function() {    
        var d = NWF$('#' + jsPriority + ' option:selected').val();
       //alert(d);
        switch (d)
  {
            case("Urgent - Immediate Attention or Response Required within 2 days"):
                 //alert(d);
                 //$(this).find('option:selected').css('color', 'red');
                 NWF$('#'+jsPriority).find(' option:selected').css('color', 'red');
                 NWF$('#'+jsPriority).css('color', 'red');
                 break;
            //case d.startsWith("Urgent"):            
            //break;
            case ("Important - High Attention or Response Required within 7 days"): 
                NWF$('#'+jsPriority).find(' option:selected').css('color', 'orange'); 
                NWF$('#'+jsPriority).css('color', 'orange');               
                break;
            case ("Normal - Review or Response Required within 14 days"): 
                //alert(d);
                NWF$('#'+jsPriority).find(' option:selected').css('color', 'green');
                NWF$('#'+jsPriority).css('color', 'green');
                break;            
        }   
});


// coloring priority
NWF$(document).ready(function() {    
NWF$('#' + jsPriority).change(function() {
        var d = NWF$('#' + jsPriority + ' option:selected').val();
       //alert(d);
        switch (d)
  {
            case("Urgent - Immediate Attention or Response Required within 2 days"):
                 //alert(d);
                 //$(this).find('option:selected').css('color', 'red');
                 NWF$('#'+jsPriority).find(' option:selected').css('color', 'red');
                 NWF$('#'+jsPriority).css('color', 'red');
                 break;
            //case d.startsWith("Urgent"):            
            //break;
            case ("Important - High Attention or Response Required within 7 days"): 
                NWF$('#'+jsPriority).find(' option:selected').css('color', 'orange'); 
                NWF$('#'+jsPriority).css('color', 'orange');               
                break;
            case ("Normal - Review or Response Required within 14 days"): 
                //alert(d);
                NWF$('#'+jsPriority).find(' option:selected').css('color', 'green');
                NWF$('#'+jsPriority).css('color', 'green');
                break;            
        }   
});
});