jQuery+ajax实现文件上传

html代码段

<input type="file" name="photo" id="photo" value="" placeholder="免冠照片">
<input type="button" onclick="postData();" value="下一步" name="" style="width:100px;height:30px;">

jQuery代码段

<script type="text/javascript">
function postData(){
    var formData = new FormData();
    formData.append("photo",$("#photo")[0].files[0]);
    formData.append("service",'App.Passion.UploadFile');
    formData.append("token",token);
    $.ajax({
        url:'http://www.baidu.com/', /*接口域名地址*/
        type:'post',
        data: formData,
        contentType: false,
        processData: false,
        success:function(res){
            console.log(res.data);
            if(res.data["code"]=="succ"){
                alert('成功');
            }else if(res.data["code"]=="err"){
                alert('失败');
            }else{
                console.log(res);
            }
        }
    })
}