## 1. 安装 *WebApiClient.JIT* 和 *Microsoft.AspNetCore.Http* ```bash Install-Package WebApiClient.JIT -Version 1.0.8 Install-Package Microsoft.AspNetCore.Http -Version 2.1.1 ``` ## 2. *IAuthApi.cs* ```csharp ///

/// 权限API ///

public interface IAuthApi : IHttpApi { ///

/// 获取小程序全局唯一后台接口调用凭据（access_token） ///

/// /// [HttpGet("https://api.weixin.qq.com/cgi-bin/token")] ITask GetAccessToken(GetAccessTokenRequest request); } ///

/// 获取小程序全局唯一后台接口调用凭据参数 ///

public class GetAccessTokenRequest { ///

/// 填写 client_credential ///

[AliasAs("grant_type")] public string GrantType { get; set; } = "client_credential"; ///

/// 小程序唯一凭证，即 AppID ///

[AliasAs("appid")] public string AppId { get; set; } ///

/// 小程序唯一凭证密钥，即 AppSecret ///

[AliasAs("secret")] public string Secret { get; set; } } ///

/// 获取小程序全局唯一后台接口调用凭据返回值 ///

public class GetAccessTokenResponse : WXBaseResponse { ///

/// 接口调用凭证 ///

[AliasAs("access_token")] public string AccessToken { get; set; } ///

/// 凭证有效时间，单位：秒。目前是7200秒之内的值。 ///

[AliasAs("expires_in")] public int ExpiresIn { get; set; } } ///

/// 微信基础返回信息 ///

public class WXBaseResponse { ///

/// 错误码： /// -1 : 系统繁忙，此时请开发者稍候再试； /// 0 : 请求成功； /// ... ... ///

[AliasAs("errcode")] public int ErrCode { get; set; } ///

/// 错误信息 ///

[AliasAs("errmsg")] public string ErrMsg { get; set; } } ``` ## 3. *IWxacodeApi.cs* 因为 *wxacode.getUnlimited* 返回的类型可能是 Json 也可能是图片，所以这里返回值类型为 `HttpResponseMessage` 。 ```csharp ///

/// 小程序码API ///

public interface IWxacodeApi : IHttpApi { ///

/// 获取小程序码，适用于需要的码数量极多的业务场景。通过该接口生成的小程序码，永久有效，数量暂无限制。 ///

/// /// /// [HttpPost("https://api.weixin.qq.com/wxa/getwxacodeunlimit")] ITask GetUnlimited([JsonContent] GetUnlimitedRequest request, [PathQuery] string access_token); } ///

/// 获取小程序码参数 ///

public class GetUnlimitedRequest { ///

/// 参数 : 最大32个可见字符，只支持数字，大小写英文以及部分特殊字符：!#$&'()*+,/:;=?@-._~，其它字符请自行编码为合法字符（因不支持%，中文无法使用 urlencode 处理，请使用其他编码方式） ///

[AliasAs("scene")] public string Scene { get; set; } ///

/// 主页 : 必须是已经发布的小程序存在的页面（否则报错），例如 pages/index/index, 根路径前不要填加 /,不能携带参数（参数请放在scene字段里），如果不填写这个字段，默认跳主页面 ///

[AliasAs("page")] public string Page { get; set; } ///

/// 二维码的宽度，单位 px，最小 280px，最大 1280px ///

[AliasAs("width")] public int width { get; set; } = 430; ///

/// 接口调用凭证 ///

[AliasAs("auto_color")] public bool AutoColor { get; set; } = false; ///

/// auto_color 为 false 时生效，使用 rgb 设置颜色例如 {"r":"xxx","g":"xxx","b":"xxx"} 十进制表示 ///

[AliasAs("line_color")] public RGBColor LineColor { get; set; } ///

/// 是否需要透明底色，为 true 时，生成透明底色的小程序 ///

[AliasAs("is_hyaline")] public bool IsHyaline { get; set; } = false; } ///

/// RGB ///

public class RGBColor { ///

/// R ///

[AliasAs("r")] public int R { get; set; } ///

/// G ///

[AliasAs("g")] public int G { get; set; } ///

/// B ///

[AliasAs("b")] public int B { get; set; } } ``` ## 4. *WXApiFactory.cs* ```csharp ///

/// 微信API工厂类 ///

public class WXApiFactory { ///

/// 注册API ///

public static void Register() { // 权限API HttpApi.Register().ConfigureHttpApiConfig(c => { }); // 小程序码API HttpApi.Register().ConfigureHttpApiConfig(c => { }); } } ``` ## 5. *ESSearchApiExtension.cs* ```csharp ///

/// 微信 Api 扩展类 ///

public static class ESSearchApiExtension { ///

/// 使用微信Api ///

/// public static void UseWXApi(this IApplicationBuilder app) { WXApiFactory.Register(); } } ``` ## 6. *Startup.cs* ```csharp ///

/// This method gets called by the runtime. Use this method to configure the HTTP request pipeline. ///

/// /// public void Configure(IApplicationBuilder app, IHostingEnvironment env) { // ... app.UseMvc(); // ... // 使用微信API app.UseWXApi(); } ``` ## 7. *WXAccessTokenUtils.cs* ```csharp ///

/// 微信接口调用凭证通用方法 ///

public class WXAccessTokenUtils { ///

/// 刷新接口调用凭证 ///

/// public static async Task RefreshAccessTokenAsync(string appId) { var response = await HttpApi.Resolve().GetAccessToken(new GetAccessTokenRequest() { AppId = appId, Secret = ZConfig.GetConfigString(ApolloConfigKey.AppSecret), }); if (response.ErrCode == 0) { // 将接口调用凭据保存到缓存 RedisUtil.Set($"{CacheKey.WXAccessTokenPrefix}_{appId}", new AccessTokenCacheModel() { AccessToken = response.AccessToken, ExpiresTime = DateTime.Now.AddSeconds(response.ExpiresIn), }, response.ExpiresIn / 60); } return response; } ///

/// 获取接口调用凭证 ///

/// /// public static async Task GetAccessTokenAsync(string appId) { var cacheKey = $"{CacheKey.WXAccessTokenPrefix}_{appId}"; // 将接口调用凭据保存到缓存 var cachedAccessToken = RedisUtil.Get(cacheKey); if (cachedAccessToken == null || cachedAccessToken.ExpiresTime < DateTime.Now) { // 没有缓存或凭证已过期时，刷新凭证 var response = await RefreshAccessTokenAsync(appId); if (response != null && response.ErrCode == 0) { return response.AccessToken; } else { return string.Empty; } } else if(cachedAccessToken.ExpiresTime.AddMinutes(-5) < DateTime.Now) { // 即将过期时重新获取凭证 var response = await RefreshAccessTokenAsync(appId); if (response != null && response.ErrCode != 0) { return response.AccessToken; } else { return cachedAccessToken.AccessToken; } } return cachedAccessToken.AccessToken; } } ``` ## 8. *QRCodeController.cs* 失败时返回的是 Json 字符串，成功时返回的是图片的 buffer。这里通过返回消息的 *ContentType* 来判断是哪种类型。 ```csharp ///

/// 获取小程序码 ///

/// /// [HttpPost("wxacode-unlimited")] public async Task GetWXACodeUnlimited(GetUnlimitedRequest request) { var appId = ZConfig.GetConfigString(ApolloConfigKey.AppID); var accessToken = await WXAccessTokenUtils.GetAccessTokenAsync(appId); var responseMessage = await HttpApi.Resolve().GetUnlimited(request, accessToken); if (responseMessage == null || responseMessage.StatusCode != System.Net.HttpStatusCode.OK) { return new Result() { IsSuccess = false, Msg = "访问微信API异常", }; } if (responseMessage.Content.Headers.ContentType.MediaType == "image/jpeg") { return new Result() { IsSuccess = true, Msg = Convert.ToBase64String(await responseMessage.Content.ReadAsByteArrayAsync()), }; } else if (responseMessage.Content.Headers.ContentType.MediaType == "application/json") { var response = JsonHelper.DeserializeObject(await responseMessage.Content.ReadAsStringAsync()); return new Result() { IsSuccess = false, Msg = response.ErrMsg, }; } return new Result() { IsSuccess = false, Msg = "未处理的二维码类型，请联系客服。", }; } ///

/// 获取小程序码图片 ///

/// /// [HttpPost("wxacode-unlimited-img")] public async Task GetWXACodeUnlimitedImage(GetUnlimitedRequest request) { var appId = ZConfig.GetConfigString(ApolloConfigKey.ZYXY_AppID); var accessToken = await WXAccessTokenUtils.GetAccessTokenAsync(appId); var responseMessage = await HttpApi.Resolve().GetUnlimited(request, accessToken); if (responseMessage != null && responseMessage.StatusCode == HttpStatusCode.OK && responseMessage.Content.Headers.ContentType.MediaType == "image/jpeg") { Response.Clear(); Response.ContentType = responseMessage.Content.Headers.ContentType.MediaType; await Response.Body.WriteAsync(await responseMessage.Content.ReadAsByteArrayAsync()); return; } Response.StatusCode = (int)HttpStatusCode.InternalServerError; } ``` ## 9. *QRCode.wxml* ```html

``` ## 参考 1. [wxacode.getUnlimited](https://developers.weixin.qq.com/miniprogram/dev/api-backend/wxacode.getUnlimited.html) 2. [auth.getAccessToken](https://developers.weixin.qq.com/miniprogram/dev/api-backend/auth.getAccessToken.html)

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