我找不到代码有什么问题，所以我使用了在互联网上找到的另一个代码，现在窗口打开了。

var file_frame;
$(\'#csv_file_button\').on(\'click\', function(event){
    event.preventDefault();
    if ( file_frame ) {
        file_frame.open();
  return;
}
// Create the media frame.
file_frame = wp.media.frames.file_frame = wp.media({
  title: $( this ).data( \'File upload\' ),
  button: {
    text: $( this ).data( \'Upload\' ),
  },
  multiple: false  // Set to true to allow multiple files to be selected
});
// When an image is selected, run a callback.
file_frame.on( \'select\', function() {
  // We set multiple to false so only get one image from the uploader
  attachment = file_frame.state().get(\'selection\').first().toJSON();
    $(\'#csv_file\').attr(\'value\',attachment.url);
});

// Finally, open the modal
file_frame.open();
});

无法确定问题所在。因此，我们需要跟踪您的代码，为此，您需要用第一个JS代码替换以下JS代码：

$(\'#csv_file_button\').click(function() {
    alert(\'Button clicked\');
        formfield = $(\'#csv_file\').attr(\'name\');
        alert(\'formfield name is >> \' + formfield);
    tb_show(\'\', \'media-upload.php?type=file&TB_iframe=true\');
        alert(\'Finally thick box randered..! No issue here\');
    return false;
}); 

如果你仍然面临同样的问题，请随时与我联系。

谢谢

首先，您需要将thickbox包含到主题中，以使用tb\\U show popup

function include_thickbox_scripts()    
{
    // include the javascript    
    wp_enqueue_script(\'thickbox\', null, array(\'jquery\'));

    // include the thickbox styles    
    wp_enqueue_style(\'thickbox.css\', \'/\'.WPINC.\'/js/thickbox/thickbox.css\', null, \'1.0\');

}

add_action(\'wp_enqueue_scripts\', \'include_thickbox_scripts\');