JS+html5实现异步上传图片显示上传文件进度条功能示例

本文实例讲述了JS+html5实现异步上传图片显示上传文件进度条功能。分享给大家供大家参考，具体如下：

<html>
  <head>
  </head>
  <body>
      <p>
  emo_album_id:<input type="text" name="emo_album_id" id="emo_album_id" value='1'>
</p>
<p>
  name:<input type="text" name="title" id="title">
</p>
      <div class="row">
        <label for="file">
          Upload Image:</label>
        <input type="file" name="fileToUpload" id="fileToUpload" multiple="multiple" onchange="fileSelected();" />
      </div>
SentenceMovie[photo]
      <div id="fileName">
      </div>
      <div id="fileSize">
      </div>
      <div id="fileType">
      </div>
      <div id="progressNumber">
      </div>
    <script>
          function fileSelected() {
            var file = document.getElementById('fileToUpload').files[0];
            if (file) {
              var fileSize = 0;
              if (file.size > 1024 * 1024)
                fileSize = (Math.round(file.size * 100 / (1024 * 1024)) / 100).toString() + 'MB';
              else
                fileSize = (Math.round(file.size * 100 / 1024) / 100).toString() + 'KB';
              document.getElementById('fileName').innerHTML = 'Name: ' + file.name;
              document.getElementById('fileSize').innerHTML = 'Size: ' + fileSize;
              document.getElementById('fileType').innerHTML = 'Type: ' + file.type;
              uploadFile();
            }
          }
          function uploadFile() {
            var fd = new FormData();
            fd.append("upload_file", document.getElementById('fileToUpload').files[0]);
            fd.append("emo_album_id", document.getElementById('emo_album_id').value);
            fd.append("title", document.getElementById('title').value);
            var xhr = new XMLHttpRequest();
            xhr.upload.addEventListener("progress", uploadProgress, false);
            xhr.addEventListener("load", uploadComplete, false);
            xhr.addEventListener("error", uploadFailed, false);
            xhr.addEventListener("abort", uploadCanceled, false);
            xhr.open("POST", "http://mysae.com/emotions/1/api/index.php/emo/upload");
            xhr.send(fd);
          }
          function uploadProgress(evt) {
            if (evt.lengthComputable) {
              var percentComplete = Math.round(evt.loaded * 100 / evt.total);
              document.getElementById('progressNumber').innerHTML = percentComplete.toString() + '%';
            }
            else {
              document.getElementById('progressNumber').innerHTML = 'unable to compute';
            }
          }
          function uploadComplete(evt) {
            /* This event is raised when the server send back a response */
            alert(evt.target.responseText);
          }
          function uploadFailed(evt) {
            alert("There was an error attempting to upload the file.");
          }
          function uploadCanceled(evt) {
            alert("The upload has been canceled by the user or the browser dropped the connection.");
          }
    </script>
  </body>
</html>

更多关于JavaScript相关内容感兴趣的读者可查看本站专题：《JavaScript+HTML5特效与技巧汇总》、《JavaScript图片操作技巧大全》、《JavaScript图形绘制技巧总结》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript数学运算用法总结》

希望本文所述对大家JavaScript程序设计有所帮助。