一、配置信息

1、微信公众平台：mp.weixin.qq.com

2、登录小程序=》 开发 -> 开发管理 -> 开发设置-> 拿到小程序专属的 AppId， Secret

3、登录公众号=》 模板Id： 广告与服务=>模板消息=>操作记录=>模板Id

4、绑定微信公众号与小程序： 广告与服务=>小程序管理=>添加关联小程序

二、实现思路

1、前端去获取到在公众号的 code

2、后端通过这个 code、appid、secret 去微信获取用户在公众号的 openId

3、后端通过 appid、secret 去微信获取 access_token

3、后端通过 access_token、templateid、openid、消息内容 给用户发送公众号模板消息

三、代码实现

1、获取用户的openId

static string UserOpenIdUrl="https://api.weixin.qq.com/sns/oauth2/access_token";

/// <summary>
/// 获取微信公众号用户openId
/// </summary>
/// <returns></returns>
public static async Task<string> GetOpenId(string pAppId, string pSecret, string pCode)
{
    try
    {
        Dictionary<string, string> pairs = new Dictionary<string, string>()
        {
            {"appid", pAppId },
            {"secret", pSecret },
            {"code", pCode },
            {"grant_type", "authorization_code" },
        };

        //获取微信公众号用户信息
        string jsonResult = null;
        using (HttpClient client = new HttpClient())
        {
            //配置请求数据
            var queryString = new FormUrlEncodedContent(pairs).ReadAsStringAsync().Result;

            //拼接url参数
            string url = UserOpenIdUrl + "?" + queryString;

            //发送http请求
            HttpResponseMessage response = await client.GetAsync(url);

            //校验请求状态是否成功
            if (response.IsSuccessStatusCode)
                jsonResult = await response.Content.ReadAsStringAsync();
            else
                jsonResult = $"Error: {response.StatusCode}";

        }
        if (string.IsNullOrEmpty(jsonResult))
            return null;

        return JObject.Parse(jsonResult)["openid"].ToString();
    }
    catch (Exception ex)
    {
        await Console.Out.WriteLineAsync(ex.Message);
        return null;
    }
}

2、获取access_token

static string GetTokenUrl="https://api.weixin.qq.com/cgi-bin/token";

 /// <summary>
/// 获取微信公众号Token
/// </summary>
/// <returns></returns>
public static async Task<string> GetToken(string appId, string secret)
{
    Dictionary<string, string> pairs = new Dictionary<string, string>()
    {
        {"appid", appId },
        {"secret", secret },
        {"grant_type", "client_credential" },
    };
    string jsonResult = null;
    using (HttpClient client = new HttpClient())
    {
        //配置请求数据
        var queryString = new FormUrlEncodedContent(pairs).ReadAsStringAsync().Result;

        //拼接url参数
        string url = GetTokenUrl + "?" + queryString;

        //发送http请求
        HttpResponseMessage response = await client.GetAsync(url);

        //校验请求状态是否成功
        if (response.IsSuccessStatusCode)
            jsonResult = await response.Content.ReadAsStringAsync();
        else
            jsonResult = $"Error: {response.StatusCode}";

    }
    if (string.IsNullOrEmpty(jsonResult))
        return null;
        
    return JObject.Parse(jsonResult)["access_token"].ToString();
}

3、发送模板消息

static string sednUrl="https://api.weixin.qq.com/cgi-bin/message/template/send?access_token={0}";

//发送指定人消息
public static async Task<bool> SendWeChat(string access_token, string templateId, List<string> openIds)
{
    try
    {
        // 准备发送模板消息需要的信息
        foreach (var openId in openIds)
        {
            dynamic content = new
            {
                touser = openId,
                template_id = templateId,
                data = new
                {
                    phrase11 = new
                    {
                        value = "测试数据",
                        color = "#173177"
                    },
                    thing5 = new
                    {
                        value = "测试过数据2222",
                        color = "#173177"
                    }
                }
            };

            string dataJson = JsonConvert.SerializeObject(content);
            string url = string.Format(sednUrl, access_token);
             
            string responseContent = null;
                
            // 使用Wechat.SDK发送模板消息
            using (HttpClient client = new HttpClient())
            {
                //配置请求数据
                StringContent requestContent = new StringContent(dataJson, Encoding.UTF8, "application/json");
            
                //发送http请求
                HttpResponseMessage response = await client.PostAsync(url, requestContent);
            
                //校验请求状态是否成功
                if (response.IsSuccessStatusCode)
                    responseContent = await response.Content.ReadAsStringAsync();
                else
                    responseContent = $"Error: {response.StatusCode}";
            
            }

        return true;
    }
    catch (Exception ex)
    {
        await Console.Out.WriteLineAsync(ex.Message);
        return false;
    }
}

以上就是c#实现的给指定用户发送公众号模板消息功能全部流程！！！