我正在尝试禁用动态创建的下拉菜单选项(取决于用户与其他菜单选项的交互)并且我遇到了一个错误,指出“null”不是一个对象。
在这行代码上:
if (document.getElementById(DropDownNames[j]+x).value = openerVals) {
我相信我有一个语法错误,但是我对 Javascript 还是很陌生,并不完全确定。
这是整个代码:
var OpeningEmployees = document.getElementById('opener');
var QuantityDDOptions = ('#opener option').length;
var openerVals = eodForm.elements["opener"].value;
var DropDownNames = new Array();
DropDownNames[0] = "ui-multiselect-opener-option-";
DropDownNames[1] = "ui-multiselect-mid-option-";
DropDownNames[2] = "ui-multiselect-closer-option-";
DropDownNames[3] = "ui-multiselect-SR-option-";
DropDownNames[4] = "ui-multiselect-CR-option-";
DropDownNames[5] = "ui-multiselect-A-option-";
DropDownNames[6] = "ui-multiselect-BD-option-";
DropDownNames[7] = "ui-multiselect-Fridge-option-";
DropDownNames[8] = "ui-multiselect-AO-option-";
DropDownNames[9] = "ui-multiselect-EPV-option-";
OpeningEmployees.onchange = function () {
for (var j = 0; j <= DropDownNames.length; j++){
for (var x = 0; x <= QuantityDDOptions; x++) {
if (document.getElementById(DropDownNames[j]+x).value = openerVals) {
document.getElementById("'"+DropDownNames[j]+x+"'").setAttribute("disabled","disabled");
感谢大家的帮助。我已经从您的帖子中进行了更改,但仍然在浏览器控制台中收到错误。请注意,下拉名称末尾的数字是动态的。随着用户被添加到数据库中,他们被添加到下拉菜单中,这就是我将 QuantityDDOptions 设置为等于选项数量的原因。选项从 0 开始。
这是更新的代码:
var OpeningEmployees = document.getElementById('opener');
var QuantityDDOptions = ('#opener option').length;
var openerVals = eodForm.elements["opener"].value;
var DropDownNames = new Array();
DropDownNames[0] = "ui-multiselect-opener-option-";
DropDownNames[1] = "ui-multiselect-mid-option-";
DropDownNames[2] = "ui-multiselect-closer-option-";
DropDownNames[3] = "ui-multiselect-SR-option-";
DropDownNames[4] = "ui-multiselect-CR-option-";
DropDownNames[5] = "ui-multiselect-A-option-";
DropDownNames[6] = "ui-multiselect-BD-option-";
DropDownNames[7] = "ui-multiselect-Fridge-option-";
DropDownNames[8] = "ui-multiselect-AO-option-";
DropDownNames[9] = "ui-multiselect-EPV-option-";
OpeningEmployees.onchange = function () {
for (var j = 0; j < DropDownNames.length; j++){
for (var x = 0; x < QuantityDDOptions; x++) {
if (document.getElementById(DropDownNames[j]+x).value == openerVals) {
document.getElementById(DropDownNames[j]+x).setAttribute("disabled","disabled");