1、微信小程序获取Access_token：

access_token具体时效看官方文档。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Web;
using TT.Utilities;

namespace DjwzApi.Com
{
    public class WeChatApi
    {
        public static string AppID = TT.Utilities.Config.ConfigureAppConfig.GetAppSettingsKeyValue("AppID");
        public static string AppSecret = TT.Utilities.Config.ConfigureAppConfig.GetAppSettingsKeyValue("AppSecret");

        private static string Access_token = "";
        private static DateTime Expires_in_time = DateTime.Now;

        static object lockObj = new object();
        /// <summary>
        /// 获取Access_token
        /// </summary>
        /// <param name="AppID"></param>
        /// <param name="AppSecret"></param>
        /// <returns></returns>
        public static string GetAccess_token(string AppID = null, string AppSecret = null)
        {
            lock (lockObj)
            {
                if (string.IsNullOrEmpty(Access_token) || ((DateTime.Now - Expires_in_time).TotalSeconds >= -30))
                {
                    lock (lockObj)
                    {
                        Access_token = "";
                        Expires_in_time = DateTime.Now;
                        AppID = AppID ?? WeChatApi.AppID;
                        AppSecret = AppSecret ?? WeChatApi.AppSecret;

                        string url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={0}&secret={1}";
                        url = string.Format(url, AppID, AppSecret);

                        var json = "";
                        try
                        {
                            json = TT.Utilities.Web.HttpClientUti.DoGet(url);
                        }
                        catch (Exception ex)
                        {
                            System.Threading.Tasks.Task.Factory.StartNew(() => utils.LogHelper.WriteLog(ex.Message));
                            throw new Exception("获取微信端access_token失败," + ex.Message);
                        }

                        //{"access_token":"12_TrAgGuiF64W8XPRXyFRFUK7SjzZptoa3ogS4mGKp-W-ni6dG_OoMNMbm_7q9lhYcx85xh-SNe3BUC_6Lg1H6FDMU7fUsKoG4NwN5EA-NVOCVUZg0OIdTvOmgHMgCxJQ1vWP__VvId4AJ2Bm_QYPdABAFNE","expires_in":7200}
                        dynamic obj = new { access_token = "", expires_in = 0, errcode = 0, errmsg = "" };
                        obj = TT.Utilities.Json.JsonHelper.DeserializeAnonymousType(json, obj);
                        if (obj.errcode == 0)
                        {
                            Expires_in_time = DateTime.Now.AddSeconds(obj.expires_in);
                            Access_token = obj.access_token;
                        }
                        return Access_token;
                    }
                }
                else
                {
                    return Access_token;
                }
            }
        }
    }
}

 

2、获取二维码

 这里实现了官网文档中提到的 接口A和接口C

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Web;

namespace DjwzApi.Com
{
    public class WxQrcode
    {
        private const string line_color = "{\"r\":\"0\",\"g\":\"0\",\"b\":\"0\"}";
        /// <summary>
        /// 接口A: 生成小程序码， 适用于需要的码数量较少的业务场景 
        /// </summary>
        /// <returns></returns>
        public static string QrcodeA(string path, int width = 430, bool auto_color = false, string line_color = line_color, bool is_hyaline = false)
        {
            string url = "https://api.weixin.qq.com/wxa/getwxacode?access_token={0}";
            var ACCESS_TOKEN = WeChatApi.GetAccess_token();
            url = string.Format(url, ACCESS_TOKEN);
            var arg = new Dictionary<string, string> { 
              {"path",