我得到了这个错误，它来自jquery框架.
它对Change事件有效，但在try 手动执行该函数时出现错误.
Uncaught TypeError: Cannot read property 'toLowerCase' of undefined -> jquery-2.1.1.js:7300
这是密码
$(document).ready(function() {
$("#CourseSelect").change(loadTeachers);
loadTeachers();
});
function loadTeachers() {
$.ajax({
type: 'GET',
url: '/Manage/getTeachers/' + $(this).val(),
dataType: 'json',
cache: false,
success:function(data) {
$('#TeacherSelect').get(0).options.length = 0;
$.each(data, function(i, teacher) {
var option = $('<option />');
option.val(teacher.employeeId);
option.text(teacher.name);
$('#TeacherSelect').append(option);
});
},
error: function() {
alert("Error while getting results");
}
});
}