网络编程 发布日期：2024/10/3 浏览次数：1
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="/UploadFiles/2021-04-02/jquery-1.7.2.min.js">
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）
<"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。