仔细核对查看过生成二维码数据，pattern确实是1，7月24号生成但是8月15日失效了，都有什么原因？

map.put("access_token", access_token);

JSONObject jsonParam = new JSONObject();
JSONObject jsonParam1 = new JSONObject();
JSONObject jsonParam2 = new JSONObject();
jsonParam2.put("scene_str",sceneStr);
jsonParam1.put("scene", jsonParam2);
jsonParam.put("action_info",jsonParam1 );         

//0：临时二维码
if("0".equals(pattern)) {
    jsonParam.put("action_name","QR_STR_SCENE");
    jsonParam.put("expire_seconds", timeLimit);
}else {
    jsonParam.put("action_name","QR_LIMIT_STR_SCENE");
}

String url= "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=" + access_token;

try {
    result = HttpUtils.postJsonData(jsonParam,url);
} catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}