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微信JS-SDK接口 + FLASK实现图片上传

2017-02-12 21:22 716 查看

 最近在做一个项目从全球各地采集图片,考虑采用微信JS-SDK来简化开发。图片会首先上传到微信的服务器,返回一个id,然后根据这个id去微信服务器获取图片。微信提供可选择的压缩图片功能。图片首先上传到微信的服务器,可以保障较好的上传稳定性。

详细内容请参考微信的官方文档:微信JS-SDK说明文档

 

运行页面如下

 

 

 

HTML

在微信demo的基础上修改,见微信JS-SDK DEMO页面

增加图片的多次选择,多次上传,删除等功能


uploadImage.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>图片上传 Demo</title>
<link rel="stylesheet" href="http://203.195.235.76/jssdk/css/style.css">
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=0">
<style>
.box{ position:relative;width:97%;}
input[type="checkbox"]{
position:absolute; right:0px;
-webkit-tap-highlight-color: rgba(0,0,0,0);
-webkit-appearance: none;
width: 24px;
height: 24px;
background-size: 100%;
outline:none;
background-image: url("data:image/png;base64,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");
}
img {
height: auto;
width: 100%;
}
.imgdiv {
height: auto;
width: 24%;
float:left;
}
</style>
</head>
<body ontouchstart="">
<div class="wxapi_container">
<div class="lbox_close wxapi_form">
<h3 id="menu-image">已选择图片</h3>
<div id="imgs"></div>
<div style="clear:both"></div>
<h3 id="upload-image">已上传图片</h3>
<div id="uploadImgs"></div>
<div style="clear:both"></div>
<span class="desc">拍照或从手机相册中选择图片</span>
<button class="btn btn_primary" id="chooseImage">选择图片</button>
<button class="btn btn_primary" id="uploadImage">上传图片</button>

<button class="btn btn_primary" id="postData">提交</button>

</div>
</div>
</body>
<script src="//cdn.bootcss.com/jquery/1.9.1/jquery.min.js"></script>
<script src="https://res.wx.qq.com/open/js/jweixin-1.0.0.js"></script>
<script type="text/javascript" charset="utf-8"
src="demo.js"></script>
<script>

//配置微信
wx.config({
debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来,若要查看传入的参数,可以在pc端打开,参数信息会通过log打出,仅在pc端时才会打印。
appId: '1234567890', // 必填,公众号的唯一标识
timestamp: {{ signature.timestamp }}, // 必填,生成签名的时间戳
nonceStr: '{{ signature.nonceStr }}', // 必填,生成签名的随机串
signature: '{{ signature.signature }}',// 必填,签名,见附录1
jsApiList: [ 'chooseImage', 'uploadImage'] // 必填,需要使用的JS接口列表,所有JS接口列表见微信sdk文档附录2
});
</script>
</html>

JS代码

 

var images = {
index:1,   //用于产生全局图片id,绑定已选择图片和已上传图片
selectIds: {},  //保存已经选择的图片id
uploadIds:{}  //保存已经上传到微信服务器的图片
};

wx.ready(function () {
// 5 图片接口
// 5.1 拍照、本地选图
$("#chooseImage").on("click", function () {
wx.chooseImage({
success: function (res) {
for (var i = 0; i < res.localIds.length; i++) {
//全局图片id,绑定微信选择图片产生的localId,将用户选择图片追加到已选择图片
var id = '' + images.index++;
images.selectIds[id] = res.localIds[i];
$('#imgs').append('<div class="imgdiv"><div class="box"><input id="' + id +'" type="checkbox"/><img src="' + res.localIds[i] + '" /></div></div>');
}
console.log('已选择了 ' + Object.keys(images.selectIds).length + ' 张图片');
}
});
});

// 5.3 上传图片
$("#uploadImage").on("click", function () {
if (Object.keys(images.selectIds).length == 0) {
alert('请先选择图片');
return;
}
var i = 0, length = Object.keys(images.selectIds).length;
var selectIds = [];  //需要上传的图片的全局图片id
for(var id in images.selectIds){
selectIds.push(id);
}
function upload() {
wx.uploadImage({
localId: images.selectIds[selectIds[i]],  //根据全局图片id获取已选择图片
isShowProgressTips: 0, // 默认为1,显示进度提示
success: function (res) {
//上传成功,images.selectIds中移除,images.uploadIds追加
//图片从已选择移到已上传区域
var selectId = selectIds[i];
localId = images.selectIds[selectId];
removeId(selectId);
$('#uploadImgs').append('<div class="imgdiv"><div class="box"><input id="' + selectId +'" type="checkbox"/><img src="' + localId + '" /></div></div>');
images.uploadIds[selectId] = res.serverId
i++;
if (i < length) {
console.log('已上传成功 ' + i + '/' + length);
upload();
} else {
alert('图片上传完毕, 已上传成功 ' + i + '/' + length);
}
},
fail: function (res) {
alert('上传失败 ' + i + '/' + length);
}
});
}
upload();
});
});

wx.error(function (res) {
alert(res.errMsg);
});

$('#postData').click(function () {
if (Object.keys(images.uploadIds).length == 0) {
alert('请先上传图片');
return false;
}

var serverIds = [];
for(var id in images.uploadIds){
serverIds.push(images.uploadIds[id]);
}
var data = {
'imgIds': serverIds
}
$.ajax({
type: "post",
async: false,
url: '/uploadImgData',
data: {data: JSON.stringify(data)},
dataType: "json",
success: function (res) {
if (res.rc === 0) {
alert('提交成功!')
} else {
alert(res.msg)
}

},
error: function (e) {
alert(JSON.stringify(e));
}
});
});

$("body").on('click', ':checkbox', function(){
var id = $(this).attr('id');
removeId(id);
});

function removeId(id){
if(id in images.selectIds){
delete images.selectIds[id]
}else{
delete images.uploadIds[id]
}
$('#' + id).parent().parent().remove();
}

 

FLASK代码

生成微信签名,参考微信JSSDK文档附录1

生成签名之前必须先了解一下jsapi_ticket,jsapi_ticket是公众号用于调用微信JS接口的临时票据。正常情况下,jsapi_ticket的有效期为7200秒,通过access_token来获取。由于获取jsapi_ticket的api调用次数非常有限,频繁刷新jsapi_ticket会导致api调用受限,影响自身业务,开发者必须在自己的服务全局缓存jsapi_ticket 。

  1. 参考以下文档获取access_token(有效期7200秒,开发者必须在自己的服务全局缓存access_token):../15/54ce45d8d30b6bf6758f68d2e95bc627.html
  2. 用第一步拿到的access_token 采用http GET方式请求获得jsapi_ticket(有效期7200秒,开发者必须在自己的服务全局缓存jsapi_ticket):https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=ACCESS_TOKEN&type=jsapi
@app.route('/uploadImgDemo', methods=['GET', 'POST'])
def uploadImgDemo():
# if not in_weixin():
#     return u'请在微信客户端打开'
now = int(time.time())
noncestr = '%s' % time.time()
url = request.url.decode('utf-8')
jsapi_ticket = get_jsapi_ticket()  #用户自定义函数,用于获取jsapi_ticket
signature = 'jsapi_ticket=%s&noncestr=%s&timestamp=%s&url=%s' % (jsapi_ticket, noncestr, now, url)
m = hashlib.sha1()
m.update(signature)
signature = m.hexdigest()
signature = {"timestamp": now, "nonceStr": noncestr, "signature": signature, "url": url}
return render_template('uploadImage.html', signature=signature)

 

接受用户提交的数据存到数据库

 

@app.route('/uploadImgData', methods=['GET', 'POST'])
def uploadImgData():
# if not in_weixin():
#    return u'请在微信客户端打开'
try:
data = request.form.get('data')
if data:
data = json.loads(data)
if data.get('imgIds'):
data['stamp'] = int(time.time())
# db.image.insert(data)  #保存id到数据库。
return json.dumps({'rc': 0, 'msg': '上传成功'})
return json.dumps({'rc': 1, 'msg': '图片不能为空'})
except Exception as e:
print e
return json.dumps({'rc': 1, 'msg': '上传失败'})

 

图片上传到微信服务器后,用python下载图片

 

access_token = None
def get_access_token(refresh = False):
global access_token
if not access_token or refresh:
access_token = access_token() #用户自定义函数,获取access_token
return access_token

#去微信服务器下载图片
def downloadPic(img_dir, img_id):
url = 'http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=%s&media_id=%s' % (get_access_token(), img_id)
down_file = '%s.jpg' % os.path.join(img_dir, img_id)
with closing(requests.get(url, stream=True)) as r:
content_length = int(r.headers.get('content-length', '0'))
if 'content-disposition' in r.headers:
m = re.match(r'attachment;\s*filename="(.*)"', r.headers.get('content-disposition'))
if m:
down_file = os.path.join(img_dir, m.group(1))
if content_length < 1000:
try:
r_json = r.json()
#提示access_token错误或过期,需要刷新token,重新下载
if r_json.get('errcode') == 40001 or r_json.get('errcode') == 42001:
get_access_token(True)
return False
except Exception as e:
print e
with open(down_file, 'wb') as f:
for data in r.iter_content(1024):
f.write(data)
return True

 

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