Javascript 如何在表单中获取参数

我的html

formData如果为空，请通读以下内容：

默认情况下，jQuery尝试将其设置为字符串，您需要关闭此功能并设置内容类型

$("#send" ).click(function() {
      var formData = new FormData($('form#csv_upload_form')[0]);
         // formData = $('#csv_upload_form').find(':input').serializeArray() --> formData is empty
            $.ajax({
                  url: "/csv/register",
                  type: "post",
                  dataType: 'json',
                  data: formData,
                  success: function(response) {
                        ..something
                   }
});

$("#send" ).click(function() {
      var formData = new FormData($('form#csv_upload_form')[0]);
         // formData = $('#csv_upload_form').find(':input').serializeArray() --> formData is empty
            $.ajax({
                  url: "/csv/register",
                  type: "post",
                  dataType: 'json',
                  data: formData,
                  success: function(response) {
                        ..something
                   }
});

$.ajax({
    url: "/csv/register",
    type: "post",
    contentType: false,
    processData: false,
    data: formData,
    success: function(response) {
        ..something
    }
});