实施数据表按钮（HTML5导出）时出现问题

Question

我是codeigniter的新手。这是IAM第一次使用数据表。该数据表可以很好地与诸如排序，搜索等功能配合使用，但是我需要实现一个导出按钮。我已经加载了datatble按钮所需的javascript文件和css文件，但没有良好的输出。这个问题可以解决

这是iam使用的javascript代码

  table = $('#user_data').DataTable({ 

       "dom": '<"top"iB>rt<"bottom"flp><"clear">',
       "buttons": [
                    {extend:'pdfHtml5',text:'Save as Pdf',key:'p'}
                    ],
    "processing": true, //Feature control the processing indicator.
    "serverSide": true, //Feature control DataTables' server-side processing mode.
    "order": [], //Initial no order.
     "bFilter":false,
     "ordering":false,
     'bLengthChange': false,
    // Load data for the table's content from an Ajax source
    "ajax": {
        "url": "fetch_print_list",
        "type": "POST",
        //"contentType": "application/json; charset=utf-8",
        "data": function ( data ) {
            data.branch = $('#branch').val();
            data.fromdate = $('#fromdate').val();
            data.view_by = $('#view_by').val();
        },
    },
    //Set column definition initialisation properties.
    "columnDefs": [
    { 
        "targets": [ 0 ], //first column / numbering column
        "orderable": false, //set not orderable
    },
    ],

});

这是我已加载的文件

 <script src="<?php echo base_url('resource/DataTables/jquery.min.js');?>"></script>

<link rel="stylesheet" type="text/css" href="<?php echo base_url('resource/DataTables/jquery.dataTables.min.css');?>"/>
<script type="text/javascript" src="<?php echo base_url('resource/DataTables/jquery.dataTables.min.js');?>"></script>

<link rel="stylesheet" type="text/css" href="<?php echo base_url('resource/DataTables/Buttons-1.5.2/css/buttons.dataTables.min.css');?>"/>
<script type="text/javascript" src="<?php echo base_url('resource/DataTables/Buttons-1.5.2/js/dataTables.buttons.min.js');?>"></script>

<script type="text/javascript" src="<?php echo base_url('resource/DataTables/pdfmake-0.1.36/pdfmake.min.js');?>"></script>
<script type="text/javascript" src="<?php echo base_url('resource/DataTables/pdfmake-0.1.36/vfs_fonts.js');?>"></script>
<script type="text/javascript" src="<?php echo base_url('resource/DataTables/Buttons-1.5.2/js/buttons.html5.min.js');?>"></script>