移动端上传图片--调用手机的相册和相机

网上百度找到一个方法不错，借鉴：代码如下

html:

<div class="head">
    <a class="btn-2">
        <input type="file" accept="image/*" id="upload" name="upload">
    </a>
</div>
<div class="photo" id="preview"></div>

css样式：

.head{
    height:40px; 
    width:100%; 
    position:relative; 
    z-index:110; 
    left:0px; 
    top:10px; 
}
.head .btn-2{
    display:block;
    width:42px;
    height:45px;
    background:url(../image/nimg37_2.png) center no-repeat;
    background-size:30px;
    position:absolute;
    top:0px;
    right:46px;
}
.head .btn-2 input {
    width:42px;
    height:45px;
    position: absolute;
    right: 0px;
    top: 0;
    opacity: 0;
}

js.js

var upload = document.getElementById('upload'),
    preview = document.getElementById('preview'),
    surebtn = document.getElementById('surebtn'),
    imgurl = '';

upload.addEventListener('change',handleFile,false);
surebtn.addEventListener('click',upLoadFile,false);

function handleFile(){
    window.URL = window.URL || window.webkitURL;
    var sUserAgent= navigator.userAgent.toLowerCase();
    var selected_file = upload.files[0];

    if(sUserAgent.match(/android/i) == "android"){
        var img = new Image();
        img.src = window.URL.createObjectURL(selected_file);
        preview.innerHTML = '';
        preview.appendChild(img);


        var reader = new FileReader();
        reader.onload = function(e) { imgurl = e.target.result; };
        reader.readAsDataURL(selected_file);

    }else{

        //判断文件类型是否为图片
        var imageType = /image.*/;

        if (!selected_file.type.match(imageType)) {
            return false;
        }

        var img = document.createElement('img');
        img.file = selected_file;
        preview.innerHTML = '';
        preview.appendChild(img);

        img.onload = function(){
            imgurl = img.src;
        }

        var reader = new FileReader();
        reader.onload = function(e) { img.src = e.target.result; };
        reader.readAsDataURL(selected_file);
    }
}

function upLoadFile(){
    var start = imgurl.indexOf(',')+1;
    dataurl = imgurl.substr(start);

    var xmlhttp = new XMLHttpRequest();
    xmlhttp.open('post','todo.php',true);
    xmlhttp.setRequestHeader('Content-Type','application/x-www-form-urlencoded;charset=utf-8');
    xmlhttp.setRequestHeader('X_Requested-With','XMLHttpRequest');
    xmlhttp.send('dataurl='+encodeURIComponent(dataurl));

    xmlhttp.onreadystatechange=function(){
        if (xmlhttp.readyState==4 && xmlhttp.status==200){
            console.log(xmlhttp.responseText)
        }
    }
}