在做微信自定义菜单开发的时候报40016 invalid button size这个错误，莫名奇妙的，2-5个菜单数目也对啊，下边分享下C#版代码：

系列化类：

[Serializable]
public class Button
{
    public string name { get; set; }
}
[Serializable]
public class SubButton : Button
{
    public string type { get; set; }
    public string key { get; set; }
}
[Serializable]
public class Menu:Button
{
    public Button[] sub_button { get; set; }
}
[Serializable]
public class WeixinMenu
{
    public List<Menu> button { get; set; }
}

特别说明，以上变量名必须小写，否则回报40016 invalid button size，好蛋疼的错误，腾讯竟然要区分大小写。

创建菜单方法：

WeixinAccessTokenModel weixinAccessTokenModel = GetWeixinAccessToken();
string url = "https://api.weixin.qq.com/cgi-bin/menu/create?access_token=" + weixinAccessTokenModel.access_token;
List<Menu> menus = new List<Menu>();
menus.Add(
    new Menu()
    {
        name = "求职招聘",
        sub_button = new SubButton[]
        {
            new SubButton()
            {
                name = "求职",
                key = "menu_qiuzhi",
                type = "click"
            },
            new SubButton()
            {
                name = "招聘",
                key = "menu_zhaopin",
                type = "click"
            }
        }
    });
menus.Add(
    new Menu()
    {
        name = "供应需求",
        sub_button = new SubButton[]
        {
            new SubButton()
            {
                name = "供应",
                key = "menu_gongying",
                type = "click"
            },
            new SubButton()
            {
                name = "需求",
                key = "menu_xuqiu",
                type = "click"
            }
        }
    });
WeixinMenu weixinMenu = new WeixinMenu() { button = menus };
JavaScriptSerializer jss = new JavaScriptSerializer();
string menusString = jss.Serialize(weixinMenu);
byte[] postBytes=Encoding.UTF8.GetBytes(menusString);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = postBytes.Length;
using (Stream reqStream = request.GetRequestStream())
{
    reqStream.Write(postBytes, 0, postBytes.Length);
}
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
System.IO.Stream responseStream = response.GetResponseStream();
System.IO.StreamReader sr = new System.IO.StreamReader(responseStream, System.Text.Encoding.GetEncoding("utf-8"));
string responseText = sr.ReadToEnd();
sr.Close();
sr.Dispose();
responseStream.Close();
string jsonData = responseText;
MenuResult menuResult = jss.Deserialize<MenuResult>(jsonData);
return url + "\n" + menuResult.Errcode + "\n" + menuResult.Errmsg;