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Ajax提交进度显示实例

概述:ajax提交比较大的文件的时候,我们希望能够看到它上传的进度,代码放下面了。

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>XMLHttpRequest 上传文件进度条示例</title>
</head>
<body>
<progress id="upload_progress" value="0" max="100"></progress>
<input id="upload_file" type="file" name="upload_file" />
<button id="btn_start">Start</button>
<button id="btn_cancel">Cancel</button>
<script type="text/javascript" src="/res/lib/jquery-1.11.3.js"></script>
<script type="text/javascript">
var xhr = new XMLHttpRequest();
var progressBar = document.getElementById(upload_progress);
$(#btn_start).click(function() {
    var uploadFile = document.getElementById(upload_file).files[0];
    var formData = new FormData();
    formData.append(upload_file, uploadFile);

    // ---------------------------------------
    // 原生xmlHttpRequest发送
    xhr.open(post, /server_url.php);
    xhr.onload = function() {
        alert(完成!);
    };
    xhr.onerror = function() {
        alert(无法连接服务器!);
    };
    xhr.upload.onprogress = function(progress) {
        if (progress.lengthComputable) {
            console.log(progress.loaded / progress.total * 100);
            progressBar.max = progress.total;
            progressBar.value = progress.loaded;
        }
    };
    xhr.upload.onloadstart = function() {
        console.log(started...);
    };
    xhr.send(formData);

    // ---------------------------------------
    // 使用ajax发送
    /**
    $.ajax({
       type: "POST",
      url: "/server_url.php",
      data: formData , //这里上传的数据使用了formData 对象
      processData: false, 
      contentType: false, //必须false才会自动加上正确的Content-Type
      //这里我们先拿到jQuery产生的 XMLHttpRequest对象,为其增加 progress 事件绑定,然后再返回交给ajax使用
      xhr: function() {
        var xhr = $.ajaxSettings.xhr();
        if (xhr.upload) {
          xhr.upload.onprogress = function(progress) {
                    if (progress.lengthComputable) {
                        console.log(progress.loaded / progress.total * 100);
                        progressBar.max = progress.total;
                        progressBar.value = http://www.mamicode.com/progress.loaded;>*/

});

$(#btn_cancel).click(function() {
    xhr.abort();
});
</script>
</body>
</html>

原理就是这样,需要在此基础上做扩展的可以随意添加自己想要的功能。

Ajax提交进度显示实例