C#实现微信小程序订阅消息推送

using System.Net.Http; using System.Text.Json; using Microsoft.Extensions.Options; public class WechatTokenService { private readonly HttpClient _httpClient; private readonly IOptions<WechatOptions> _options; private string _cachedToken; private DateTime _tokenExpireTime; public WechatTokenService(HttpClient httpClient, IOptions<WechatOptions> options) { _httpClient = httpClient; _options = options; } public async Task<string> GetAccessTokenAsync() { // 检查缓存是否有效（提前5分钟刷新） if (!string.IsNullOrEmpty(_cachedToken) && DateTime.Now < _tokenExpireTime) { return _cachedToken; } string url = string.Format(_options.Value.AccessTokenUrl, _options.Value.AppId, _options.Value.AppSecret); var response = await _httpClient.GetAsync(url); var json = await response.Content.ReadAsStringAsync(); using var doc = JsonDocument.Parse(json); _cachedToken = doc.RootElement.GetProperty("access_token").GetString(); int expiresIn = doc.RootElement.GetProperty("expires_in").GetInt32(); _tokenExpireTime = DateTime.Now.AddSeconds(expiresIn - 300); // 提前5分钟刷新 return _cachedToken; } }

public class SubscribeMessageService { private readonly HttpClient _httpClient; private readonly WechatTokenService _tokenService; private readonly IOptions<WechatOptions> _options; public SubscribeMessageService(HttpClient httpClient, WechatTokenService tokenService, IOptions<WechatOptions> options) { _httpClient = httpClient; _tokenService = tokenService; _options = options; } /// <summary> /// 发送订阅消息 /// </summary> /// <param name="openId">用户的OpenId</param> /// <param name="page">点击消息跳转的页面路径</param> /// <param name="data">模板数据，key为模板字段名</param> public async Task<SendResult> SendSubscribeMessageAsync( string openId, string page, Dictionary<string, string> data) { var token = await _tokenService.GetAccessTokenAsync(); var url = string.Format(_options.Value.SendMessageUrl, token); // 构造模板数据 var msgData = new Dictionary<string, object>(); foreach (var item in data) { msgData[item.Key] = new { value = item.Value }; } var requestBody = new { touser = openId, template_id = _options.Value.TemplateId, page = page, data = msgData, miniprogram_state = "formal" // 正式版 }; var json = JsonSerializer.Serialize(requestBody); var content = new StringContent(json, Encoding.UTF8, "application/json"); var response = await _httpClient.PostAsync(url, content); var resultJson = await response.Content.ReadAsStringAsync(); using var doc = JsonDocument.Parse(resultJson); var errcode = doc.RootElement.GetProperty("errcode").GetInt32(); var errmsg = doc.RootElement.GetProperty("errmsg").GetString(); return new SendResult { Success = errcode == 0, ErrCode = errcode, ErrMsg = errmsg }; } } public class SendResult { public bool Success { get; set; } public int ErrCode { get; set; } public string ErrMsg { get; set; } } public class WechatOptions { public string AppId { get; set; } public string AppSecret { get; set; } public string TemplateId { get; set; } public string AccessTokenUrl { get; set; } public string SendMessageUrl { get; set; } }

builder.Services.Configure<WechatOptions>(builder.Configuration.GetSection("Wechat")); builder.Services.AddHttpClient(); builder.Services.AddScoped<WechatTokenService>(); builder.Services.AddScoped<SubscribeMessageService>();

[ApiController] [Route("api/[controller]")] public class MessageController : ControllerBase { private readonly SubscribeMessageService _msgService; public MessageController(SubscribeMessageService msgService) { _msgService = msgService; } [HttpPost("send")] public async Task<IActionResult> Send([FromBody] SendRequest request) { var data = new Dictionary<string, string> { ["thing1"] = "您的订单已发货", // 对应模板中的thing1 ["time2"] = DateTime.Now.ToString("yyyy-MM-dd HH:mm"), // 对应time2 ["thing3"] = "请注意查收" // 对应thing3 }; var result = await _msgService.SendSubscribeMessageAsync( request.OpenId, "pages/order/detail?id=123", data ); if (result.Success) { return Ok(new { code = 0, msg = "发送成功" }); } // 43101表示用户未授权或拒绝授权 if (result.ErrCode == 43101) { return BadRequest(new { code = 43101, msg = "用户未授权订阅" }); } return BadRequest(result); } } public class SendRequest { public string OpenId { get; set; } }

// 页面js Page({ onSubscribe() { wx.requestSubscribeMessage({ tmplIds: ['你的模板ID'], // 最多3个 success(res) { // res[templateId] 可能为 'accept'、'reject'、'ban'、'filter' if (res['你的模板ID'] === 'accept') { // 用户同意，可调用后端接口发送消息 wx.request({ url: 'https://你的域名/api/message/send', method: 'POST', data: { openId: '用户的openid' } }); } }, fail(err) { console.error('订阅失败', err); } }); } });