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js HTML5多图片上传及预览实例解析(不含前端的文件分割)

时间:2021-07-01 10:21:17 帮助过:12人阅读

本文实例为大家分享了js HTML5多图片上传及预览实例,供大家参考,具体内容如下

主要运用 
1、HTML5 files可以选择多文件,以及获取多文件信息 
2、XMLHTTPRequest对象,发送HTTP传输请求 
3、将每一个文件放在FormData,进行传输 
4、利用readAsDataURL将图片内容直接变成url,放在img标签的src当中,生成可预览的图片 

html+css+js代码 

<!DOCTYPE html>
<head>
<meta http-equiv="Content-Type" content="text/html" charset="utf-8" />
<title>test html FileReader</title>
<style type="text/css">
html,body,header,footer,div,ul,li,h1,h2,h3,h4,h5,h6,label,input,textarea,p,span,a{
 padding: 0;
 margin: 0;
}
img {
 border: 0;
}
em,strong{
 font-weight: normal;
 font-style: normal;
}
ul {
 list-style: none;
}
h1,h2,h3,h4,h5,h6 {
 font-weight: normal;
 font-size: 100%;
}
a,a:after{
 text-decoration:none;
}
.photo_wrap{
 clear:both;
}
.photo_wrap li{
 margin:10px;
 width:150px;
 float:left;
}
.photo_box {
 height:150px;
 width:150px;
 overflow:hidden;
 position:relative;
}
.photo_box .img1{
 height:150px;
}
.photo_box .img2{
 width:150px;
}
.upload_result{
 height:50px;
}
.btns{
 position:relative;
 height:40px;
 width:100px;
 float:left;
}
.btn{
 height:40px;
 line-height:40px;
 color:#FFF;
 display:block;
 border-radius:3px;
 text-align:center;
 background-color: #FF5581; /* Old browsers */
 background-image: -moz-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); /* FF3.6+ */
 background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#FA7B9C), color-stop(100%,#FF5581)); /* Chrome,Safari4+ */
 background-image: -webkit-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); /* Chrome10+,Safari5.1+ */
 background-image: -o-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); /* Opera 11.10+ */
 background-image: -ms-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); /* IE10+ */
 background-image: linear-gradient(to bottom,#FA7B9C 0%, #FF5581 100%); /* W3C */
 filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#FA7B9C', endColorstr='#FF5581',GradientType=0 ); /* IE6-8 */
 box-shadow:0 1px 0 rgba(255, 255, 255, 0.3) inset, 0 1px 2px rgba(0, 0, 0, 0.3);
}
.btn_add_pic{
 width:100px;
 position:absolute;
 top:0;
 left:0;
}
.btn_upload{
 width:100px;
 margin:0 10px 10px;
 float:left;
}
.btn:hover,
.btn_cur{
 background-color: #FB99B1; /* Old browsers */
 background-image: -moz-linear-gradient(top,#FB99B1 0%, #FF5581 100%); /* FF3.6+ */
 background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#FB99B1), color-stop(100%,##FF5581)); /* Chrome,Safari4+ */
 background-image: -webkit-linear-gradient(top,#FB99B1 0%, #FF5581 100%); /* Chrome10+,Safari5.1+ */
 background-image: -o-linear-gradient(top,#FB99B1 0%, #FF5581 100%); /* Opera 11.10+ */
 background-image: -ms-linear-gradient(top,#FB99B1 0%, #FF5581 100%); /* IE10+ */
 background-image: linear-gradient(to bottom,#FB99B1 0%, #FF5581 100%); /* W3C */
 filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#FB99B1', endColorstr='#FF5581',GradientType=0 ); /* IE6-8 */
}
.file_input_wrap{
 position:absolute;
 top:0;
 left:0;
 width:100px;
 height:40px;
}
.file_input_wrap label{
 width:100%;
 height:100%;
 display:block;
 opacity:0;
 cursor:pointer;
}
.file_input_wrap input{
 opacity:0;
 filter:alpha(opacity=0);/*ie8及以下*/
 position:absolute;
 top:7px;
 right:173px;
 cursor:pointer;
 width:95px;
}
.photo_box .icon_pos{
 height:20px;
 width:20px;
 display:block;
 position:absolute;
 right:0;
 bottom:0;
}
.photo_box .loading{
 height:10px;
 display:block;
 position:absolute;
 left:0;
 bottom:0;
 background-image:url(loading.gif);
}
.sucess_icon{
 background-image:url(icons_01.png);
 background-position:0 0;
}
.error_icon{
 background-image:url(icons_01.png);
 background-position:-20px 0;
}
</style>
</head>

<body>
<div class="btns">
 <a class="btn btn_add_pic" id="J_add_pic" href="javascript:;">添加图片</a>
 <div class="file_input_wrap">
 <input type="file" id="file" name="file" accept="image/*" multiple onChange="fileInfo(this)" />
 <label id="J_add_area"></label>
 </div>
</div>
<a class="btn btn_upload" id="J_upload" href="javascript:;">开始上传</a>
<div id="J_photo_wrap">
 <ul class="photo_wrap">
 </ul>
</div>
</body>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript"> 
 var img_index = new Array();
 
 function upload_img(){
 var j=0;
 img();
 function img(){
 //1.创建XMLHTTPRequest对象
 if (img_index.length > 0){
 var singleImg = img_index[j];
 var xmlhttp;
 if (window.XMLHttpRequest) {
 //IE7+, Firefox, Chrome, Opera, Safari
 xmlhttp = new XMLHttpRequest;
 
 //针对某些特定版本的mozillar浏览器的bug进行修正
 if (xmlhttp.overrideMimeType) {
 xmlhttp.overrideMimeType('text/xml');
 };
 } else if (window.ActiveXObject){
 //IE6, IE5
 xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
 };
 
 if(xmlhttp.upload){
 //进度条
 xmlhttp.upload.addEventListener("progress",
 function(e) {
 if (e.lengthComputable) {
 var load_percent = (e.loaded / e.total) * 100;
 $('#J_photo_wrap ul li').eq(j).find('.loading').css('width',load_percent+'%');
 }
 },
 false);
 //2.回调函数
 //onreadystatechange是每次 readyState 属性改变的时候调用的事件句柄函数
 xmlhttp.onreadystatechange = function(e){
 if(xmlhttp.readyState==4){
 if(xmlhttp.status==200){
  var json = eval('(' + xmlhttp.responseText + ')');
  if(json.status == 1){
  $('#J_photo_wrap ul li').eq(j).find('.upload_result').text(singleImg.name+'上传完成');
  $('#J_photo_wrap ul li').eq(j).find('.loading').hide();
  $('#J_photo_wrap ul li').eq(j).find('.icon_pos').addClass('sucess_icon');
  }else{
  $('#J_photo_wrap ul li').eq(j).find('.upload_result').text(singleImg.name+'上传失败');
  $('#J_photo_wrap ul li').eq(j).find('.loading').hide();
  $('#J_photo_wrap ul li').eq(j).find('.icon_pos').addClass('error_icon');
  } 
 }else{
  $('#J_photo_wrap ul li').eq(j).find('.upload_result').text(singleImg.name+'上传失败');
  $('#J_photo_wrap ul li').eq(j).find('.loading').hide();
  $('#J_photo_wrap ul li').eq(j).find('.icon_pos').addClass('error_icon');
 }
 if (j < img_index.length - 1) {
  j++;
  img();
 }
 }
 };
 
 //3.设置连接信息
 //初始化HTTP请求参数,但是并不发送请求。
 //第一个参数连接方式,第二是url地址,第三个true是异步连接,默认是异步
 //使用post方式发送数据
 xmlhttp.open("POST","upload.php",true);
 
 //4.发送数据,开始和服务器进行交互
 //发送 HTTP 请求,使用传递给 open() 方法的参数,以及传递给该方法的可选请求中如果true, send这句话会立即执行
 //如果是false(同步),send会在服务器数据回来才执行
 //get方法在send中不需要内容
 var formdata = new FormData();
 formdata.append("FileData", singleImg);
 xmlhttp.send(formdata);
 }
 //}
 }
 }
 };
 
 $('#J_upload').click(function(){
 upload_img();
 });
 
 $('#J_add_area').hover(
 function(){
 $('#J_add_pic').addClass('btn_cur');
 },
 function(){
 $('#J_add_pic').removeClass('btn_cur');
 }
 );
 $('#J_add_area').click(function(){
 $('#file').click();
 });
 function resize(img){
 if(img.offsetHeight>img.offsetWidth){
 $(img).removeClass('img1').addClass('img2');
 }else{
 $(img).removeClass('img2').addClass('img1');
 }
 }
 function fileInfo(source){
 var ireg = /image\/.*/i;
 var files = source.files;
 var name,size,type;
 
 for(var i = 0, f; f = files[i]; i++) {
 name = f.name;
 size = f.size;
 type = f.type;
 
 if(!type.match(ireg)) {
  $('#J_photo_wrap ul').append('<li><div class="photo_box">'+name+'不是图片<span class="loading"></span><span class="icon_pos"></span></div><div class="upload_result"></div></div></li>');
 }else{
 img_index.push(f);
 if(size>1048576){
 $('#J_photo_wrap ul').append('<li><div class="photo_box">'+name+'太大,无法生成预览<span class="loading"></span><span class="icon_pos"></span></div><div class="upload_result"></div></li>');
 }else{
 if(window.FileReader) { 
 var fr = new FileReader(); 
 fr.onload = (function(f) {
 return function(e){
 $('#J_photo_wrap ul').append('<li><div class="photo_box"><img onload="resize(this);" src="'+this.result+'"/><span class="loading"></span><span class="icon_pos"></span></div><div class="upload_result"></div></li>');
 };
 })(f);
 fr.readAsDataURL(f);
 } 
 }
 }
 }
 };
</script> 
</html>

php收到文件的代码(这里只获取文件名字、类型、大小,没有进行其它操作) 

<?php
 $name = $_FILES['FileData']['name'];
 $type = $_FILES['FileData']['type'];
 $size = $_FILES['FileData']['size'];
 
 $return = array (
 "name" => $name,
 "type" => $type,
 "size" => $size,
 "status" => 1
 );
 
 $return = json_encode($return);
 
 echo $return;
?>

存在的问题
1、为了生成缩略图,readAsDataURL读取文件内容会占用内存,所以大图片会造成浏览器卡住或者奔溃
2、上传没有进行分段处理

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

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