javascript实现网易邮箱多附件上传功能代码

来源：互联网发布：推荐一本自学java的书编辑：程序博客网时间：2024/05/02 01:30

本文采用javascript＋样式表实现了仿网易邮箱多附件上传功能代码，望大家喜欢！
<html>
<head>
<title>Add Files</title>
<style>
a.addfile {
background-image:url(http://p.mail.163.com/js31style/lib/0703131650/163blue/f1.gif);
background-repeat:no-repeat;
background-position:-823px -17px;
display:block;
float:left;
height:20px;
margin-top:-1px;
position:relative;
text-decoration:none;
top:0pt;
width:80px;
}
input.addfile {
/*left:-18px;*/
}
input.addfile {
cursor:pointer !important;
height:18px;
left:-13px;
filter:alpha(opacity=0);
position:absolute;
top:5px;
width:1px;
z-index: -1;
}
</style>

<script type="text/javascript">
function MultiSelector(list_target, max)
{
    // Where to write the list
    this.list_target = list_target;
    // How many elements?
    this.count = 0;
    // How many elements?
    this.id = 0;
    // Is there a maximum?
    if (max)
    {
        this.max = max;
    }
    else
    {
        this.max = -1;
    };

      /**
      * Add a new file input element
      */
      this.addElement = function(element)
      {
         // Make sure it's a file input element
          if (element.tagName == 'INPUT' && element.type == 'file')
          {
              // Element name -- what number am I?
              element.name = 'file_' + this.id++;
              // Add reference to this object
              element.multi_selector = this;
              // What to do when a file is selected
              element.onchange = function()
              {
                  // New file input
                  var new_element = document.createElement('input');
                  new_element.type = 'file';
                  new_element.size = 1;
                  new_element.className = "addfile";
                  // Add new element
                  this.parentNode.insertBefore(new_element, this);
                  // Apply 'update' to element
                  this.multi_selector.addElement(new_element);
                  // Update list
                this.multi_selector.addListRow(this);
                  // Hide this: we can't use display:none because Safari doesn't like it
                this.style.position = 'absolute';
                this.style.left = '-1000px';
            };

            // If we've reached maximum number, disable input element
              if (this.max != -1 && this.count >= this.max)
              {
                element.disabled = true;
            };
              // File element counter
            this.count++;
            // Most recent element
            this.current_element = element;
        }
        else
        {
            // This can only be applied to file input elements!
            alert('Error: not a file input element');
        };
    };

    /**
     * Add a new row to the list of files
     */
    this.addListRow = function(element)
    {
        // Row div
        var new_row = document.createElement('div');
          // Delete button
        var new_row_button = document.createElement('input');
          new_row_button.type = 'button';
        new_row_button.value = 'Delete';
          // References
        new_row.element = element;
        // Delete function
        new_row_button.onclick = function()
        {
            // Remove element from form
            this.parentNode.element.parentNode.removeChild(this.parentNode.element);
              // Remove this row from the list
            this.parentNode.parentNode.removeChild(this.parentNode);
             // Decrement counter
            this.parentNode.element.multi_selector.count--;
              // Re-enable input element (if it's disabled)
            this.parentNode.element.multi_selector.current_element.disabled = false;
              // Appease Safari
            // without it Safari wants to reload the browser window
            // which nixes your already queued uploads
            return false;
        };
        // Set row value
        new_row.innerHTML = element.value + " ";
        // Add button
        new_row.appendChild(new_row_button);
        // Add it to the list
        this.list_target.appendChild(new_row);
    };
};
</script>
</head>

<body>

<form enctype="multipart/form-data" action="http://127.0.0.1:8080/xxx/fileUploadAction.action" method="post">

<a href="javascript:void(1==1);" class="addfile" style="cursor: default;" hidefocus="true">
<input id="my_file_element" class="addfile" type="file" name="file_1" size="1" title="点击选择附件">
</a>
<input type="submit" value="上传">
</form>

Files:

<div id="files_list" style="padding:5px;border:1px;border-style:solid;border-color:#0000ff;height:100px;width:600px;"></div>
<script>

var multi_selector = new MultiSelector(document.getElementById('files_list'), 100);

multi_selector.addElement(document.getElementById('my_file_element'));
</script>
</body>
</html>