js HTML5多图片上传及预览实例解析（不含前端的文件分割）

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 

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; 
 background-image: -moz-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); 
 background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#FA7B9C), color-stop(100%,#FF5581)); 
 background-image: -webkit-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); 
 background-image: -o-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); 
 background-image: -ms-linear-gradient(top,#FA7B9C 0%, #FF5581 100%); 
 background-image: linear-gradient(to bottom,#FA7B9C 0%, #FF5581 100%); 
 filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#FA7B9C', endColorstr='#FF5581',GradientType=0 ); 
 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; 
 background-image: -moz-linear-gradient(top,#FB99B1 0%, #FF5581 100%); 
 background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#FB99B1), color-stop(100%,##FF5581)); 
 background-image: -webkit-linear-gradient(top,#FB99B1 0%, #FF5581 100%); 
 background-image: -o-linear-gradient(top,#FB99B1 0%, #FF5581 100%); 
 background-image: -ms-linear-gradient(top,#FB99B1 0%, #FF5581 100%); 
 background-image: linear-gradient(to bottom,#FB99B1 0%, #FF5581 100%); 
 filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#FB99B1', endColorstr='#FF5581',GradientType=0 ); 
}
.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);
 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;
}





 添加图片
 
 
 
 

开始上传

 

 



 

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,
 "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考高分网。