<script>
//ajax2.0
$("#feature").change(function(){
var formData = new FormData();
formData.append('preview',this.files[0]);
$.ajax({
url:'http://www.baixiu.com/admin/API/06.imgPreview.php',
data:formData,
type:'post',
processData:false,//不自动格式化数据
contentType:false,//不自动设置请求头
success:function(backData){
console.log(backData);
$('.help-block').attr('src',backData).show();
}
})
})