
这里我要使用的是form法。通过为表单元素设置enctype=”multipart/form-data”属性,让表单提交的数据以二进制编码的方式提交,在接收此请求的Servlet中用二进制流来获取内容,就可以取得上传文件的内容,从而实现文件的上传。
表单元素的enctype属性指定的是表单数据的编码方式,该属性有3个值:

在网上找到了两种方式,PHP配合apc实现和利用uploadprogress实现,这次我要使用的是uploadprogress,点击地址可以下载到php相应版本的dll。安装php_uploadprogress.dll扩展,重启apache。

进度条实现原理:

这里用到了一个iframe无刷新上传文件的方法。

上传完成后的样子如图:
<body><div style="padding:20px"> <form action="action.php" enctype="multipart/form-data" method="post" target="iframeUpload"><iframe name="iframeUpload" width="400" height="400" frameborder="1"></iframe><input type="hidden" name="UPLOAD_IDENTIFIER" value="1" /><input id="file1" name="file1" type="file"/> <input value="上传" type="submit" onclick="startProgress()"/></form></div><div style="width: 500px; height: 20px;border:1px solid red"><div style="position: relative; height: 20px; background-color: purple; width: 0%;" class="barinner"></div></div><div id="showNum"></div><div class="prbar"> <div class="prpos barinner"></div></div> </body>上面的HTML代码中要注意下UPLOAD_IDENTIFIER,这个是用来定位查看哪个文件的上传进度的。我这里就写死为一个1,大家可以写成一个php生成的随机数。下面是JS脚本:
var proNum=0; var loop=0; var progressResult = ""; var interval; function sendURL() {$.ajax({ type : "GET", url : "getprogress.php", async : true, cache : false, dataType : "json",data: "progress_key=" + $("input[name=UPLOAD_IDENTIFIER]").val(),success : function(e) {proNum=parseInt(e);if(e){ $(".barinner").css("width", proNum+"%");$("#showNum").html(proNum+"%");setTimeout("getProgress()", 200); }else{ if(interval == 1){$(".barinner").css("width", "100%"); $("#showNum").html("100%");}}}}); } function getProgress(){loop++;sendURL(); } function startProgress(){interval = 1; $(".barinner").css("width", proNum+"%");$("#showNum").html(proNum+"%");setTimeout("getProgress()", 500); }下面是getprogress.php文件中的内容: <?phpif (function_exists("uploadprogress_get_info")) {$info = uploadprogress_get_info($_GET["progress_key"]);if(!empty($info)){ if(($info["bytes_uploaded"] < $info["bytes_total"]) && !empty($info["bytes_uploaded"]) && !empty($info["bytes_total"])){$proNum = floor(($info["bytes_uploaded"]/$info["bytes_total"])*100); }else{$proNum = 100; } echo $proNum;}else{ echo 0;} }在上传完成后,我展示了两种进度条的CSS,第二种是用最新的CSS3写的。用到了一些CSS3的动画属性。
.prbar {margin:5px;width:500px;background-color:#dddddd;overflow:hidden;/* 边框效果 */border: 1px solid #bbbbbb;-moz-border-radius: 15px;border-radius: 15px;/* 为进度条增加阴影效果 */-webkit-box-shadow: 0px 2px 4px #555555;-moz-box-shadow: 0px 2px 4px #555555;box-shadow: 0px 2px 4px #555555;} /* No rounded corners for Opera, because the overflow:hidden dont work with rounded corners */ doesnotexist:-o-prefocus, .prbar { border-radius:0px; } .prpos {width:0%;height:30px;background-color:#3399ff;border-right:1px solid #bbbbbb;/* CSS3 进度条渐变 */transition: width 2s ease;-webkit-transition: width 0s ease;-o-transition: width 0s ease;-moz-transition: width 0s ease;-ms-transition: width 0s ease;/* CSS3 Stripes */background-image: linear-gradient(135deg,#3399ff 25%,#99ccff 25%,#99ccff 50%, #3399ff 50%, #3399ff 75%,#99ccff 75%,#99ccff 100%);background-image: -moz-linear-gradient(135deg,#3399ff 25%,#99ccff 25%,#99ccff 50%, #3399ff 50%, #3399ff 75%,#99ccff 75%,#99ccff 100%);background-image: -ms-linear-gradient(135deg,#3399ff 25%,#99ccff 25%,#99ccff 50%, #3399ff 50%, #3399ff 75%,#99ccff 75%,#99ccff 100%);background-image: -o-linear-gradient(135deg,#3399ff 25%,#99ccff 25%,#99ccff 50%, #3399ff 50%, #3399ff 75%,#99ccff 75%,#99ccff 100%);background-image: -webkit-gradient(linear, 100% 100%, 0 0,color-stop(.25, #99ccff), color-stop(.25, #3399ff),color-stop(.5, #3399ff),color-stop(.5, #99ccff),color-stop(.75, #99ccff),color-stop(.75, #3399ff),color-stop(1, #3399ff));background-image: -webkit-linear-gradient(135deg,#3399ff 25%,#99ccff 25%,#99ccff 50%, #3399ff 50%, #3399ff 75%,#99ccff 75%,#99ccff 100%);background-size: 40px 40px;/* Background stripes animation */animation: bganim 3s linear 2s infinite;-moz-animation: bganim 3s linear 2s infinite;-webkit-animation: bganim 3s linear 2s infinite;-o-animation: bganim 3s linear 2s infinite;-ms-animation: bganim 3s linear 2s infinite; } @keyframes bganim {from {background-position:0px;} to { background-position:40px;} } @-moz-keyframes bganim {from {background-position:0px;} to { background-position:40px;} } @-webkit-keyframes bganim {from {background-position:0px;} to { background-position:40px;} } @-o-keyframes bganim {from {background-position:0px;} to { background-position:40px;} } @-ms-keyframes bganim {from {background-position:0px;} to { background-position:40px;} }以上就是本文的全部内容,希望对大家的学习有所帮助。