基于.NetCore2.1。服务类库采用.Net Standard2.0，兼容.net 4.6.1消息推送服务

基于.NetCore2.1。服务类库采用.Net Standard2.0，兼容.net 4.6.1消息推送服务

https://www.cnblogs.com/ibeisha/p/weixinServer.html

关于微信公众号服务的中间件，基于.NetCore2.1。服务类库采用.Net Standard2.0，兼容.net 4.6.1。

整体思路是，设计一个中间件，提供微信消息推送服务。目前实现了，接收微信消息推送后，根据消息类型，对事件消息和被动接收消息分别进行了处理。

在中间件和服务之间，创建一个服务提供类，拥有提供消息的处理逻辑，开发者，可以实现服务提供接口，完成自己的逻辑。下面，让我们看看关于中间件的代码设计：

这里，我新建了一个名为WeiXinMiddleware的类，代码如下：

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///

///

///

public class WeiXinMiddleware

{

///

///

///

private RequestDelegate Next = null;

    /// <summary>
    /// <![CDATA[配置]]>
    /// </summary>
    public IConfiguration Configuration { get; }

    /// <summary>
    /// <![CDATA[中间件配置信息]]>
    /// </summary>
    public OAuth.WeiXinServerOptions ServerOptions { get; set; }

    /// <summary>
    /// <![CDATA[构造]]>
    /// </summary>
    /// <param name="requestDelegate"></param>
    /// <param name="configuration"></param>
    public WeiXinMiddleware(RequestDelegate requestDelegate, IConfiguration configuration, OAuth.WeiXinServerOptions serverOptions)
    {
        Next = requestDelegate;
        Configuration = configuration;
        ServerOptions = serverOptions;
    }

    /// <summary>
    /// <![CDATA[调用]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public async Task Invoke(HttpContext context)
    {if (context.Request.Path == ServerOptions.NotifyPath)
        {
            //微信服务
            if (ServerOptions.WeiXinServerProvider == null) ServerOptions.WeiXinServerProvider = (OAuth.IWeiXinServerProvider)context.RequestServices.GetService(typeof(OAuth.IWeiXinServerProvider));
            await ServerOptions.WeiXinServerProvider.Run(context, Configuration);
            return;
        }
        await Next.Invoke(context);
    }
}

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代码其实很简单，就是在类内部定义一个Invoke任务，再声明一个Next属性，用于请求的下一步处理委托。在中间件的构造函数中，进行了注入，其中有一个

WeiXinServerOptions 类，它便是定义中间件所需的配置信息，也是对外提供的接口，让我们看看具体的代码：

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///

///

///

public class WeiXinServerOptions

{

///

///

///

public PathString NotifyPath { get; set; }

    /// <summary>
    ///
    /// </summary>
    private IWeiXinServerProvider _ServerProvider = null;

    /// <summary>
    /// <![CDATA[微信服务提供程序]]>
    /// </summary>
    public IWeiXinServerProvider WeiXinServerProvider
    {
        get
        {
            return _ServerProvider;
        }
        set
        {
            _ServerProvider = value;
            _ServerProvider.ServerOptions = this;
        }
    }

    /// <summary>
    /// <![CDATA[当接收到消息时]]>
    /// </summary>
    public Func<HttpContext, Task> OnRecieveAsync { get; set; }

    /// <summary>
    /// <![CDATA[扫描事件]]>
    /// </summary>
    public Func<WeiXinContext, Task> OnScanAsync { get; set; }

    /// <summary>
    /// <![CDATA[关注事件]]>
    /// </summary>
    public Func<WeiXinContext, Task> OnSubscribeAsync { get; set; }

    /// <summary>
    /// <![CDATA[取消关注]]>
    /// </summary>
    public Func<WeiXinContext, Task> OnUnsubscribeAsync { get; set; }

    /// <summary>
    /// <![CDATA[菜单点击事件]]>
    /// </summary>
    public Func<WeiXinContext, Task> OnClickAsync { get; set; }

    /// <summary>
    /// <![CDATA[点击链接]]>
    /// </summary>
    public Func<WeiXinContext, Task> OnViewAsync { get; set; }

    /// <summary>
    /// <![CDATA[上报地理位置]]>
    /// </summary>
    public Func<WeiXinContext, Task> OnLocationAsync { get; set; }

    /// <summary>
    /// <![CDATA[被动接收普通消息]]>
    /// </summary>
    public Func<HttpContext, Task> OnRecieveMessageAsync { get; set; }
}

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这个类中，定义了中间件要拦截处理的URL，以及时间消息的处理委托，有了这些委托，我们就可以很灵活的实现在接收到微信推送消息后的逻辑处理。

这个类中，还定义了一个WeiXinServerProvider属性，它是接口IWeiXinServerProvider的派生，让我们看看它定义的成员吧！

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public interface IWeiXinServerProvider

{

    /// <summary>
    ///
    /// </summary>
    OAuth.WeiXinServerOptions ServerOptions { get; set; }

    /// <summary>
    ///
    /// </summary>
    /// <param name="context"></param>
    /// <param name="configuration"></param>
    /// <param name="serverOptions"></param>
    /// <returns></returns>
    Task Run(HttpContext context, IConfiguration configuration);
}

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很简单吧，一个属性，一个运行任务的函数。

上面几个类是我服务的核心，下面我又创建了2个扩展类，分别为添加中间件和IOC注入服务。

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///

///

///

public static class WeiXinMiddlewareExtensions

{

    /// <summary>
    /// <![CDATA[]]>
    /// </summary>
    /// <param name="app"></param>
    /// <param name="serverOptions"></param>
    public static void UseWeiXinServer(this IApplicationBuilder app, OAuth.WeiXinServerOptions serverOptions)
    {
        app.UseMiddleware<Middleware.WeiXinMiddleware>(serverOptions);
    }
}

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下面是IOC注入的扩展方法：

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///

///

///

public static class WeiXinServiceCollectionExtensions

{

///

///

///

///

public static void AddWeiXinServer(this IServiceCollection services)

{

services.AddSingleton(typeof(OAuth.IWeiXinServerProvider), typeof(OAuth.WeiXinServer));//单例：IOC注册服务类型

}

}

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完成以上代码后，最后让我们再Start类中，进行服务的配置。

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public class Startup

{

public Startup(IConfiguration configuration)

{

Configuration = configuration;

}

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.Configure<CookiePolicyOptions>(options =>
        {
            // This lambda determines whether user consent for non-essential cookies is needed for a given request.
            options.CheckConsentNeeded = context => true;
            options.MinimumSameSitePolicy = SameSiteMode.None;
        });

        services.AddWeiXinServer();//IOC注册服务类型
        services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
    }

    /// <summary>
    ///
    /// </summary>
    /// <param name="app"></param>
    /// <param name="env"></param>
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }

        //使用微信中间件
        app.UseWeiXinServer(new OAuth.WeiXinServerOptions()
        {
            NotifyPath = new PathString("/OAuth/WeiXin"),
            //WeiXinServerProvider = new OAuth.WeiXinServer(),//此处也可也手动设置，默认通过IOC容器创建WeiXinServer实例。
            OnScanAsync = (context) => { return Task.Delay(0); },
            OnClickAsync = (context) => { return Task.Delay(0); },
            OnSubscribeAsync = (context) => { return Task.Delay(0); },
            OnUnsubscribeAsync = (context) => { return Task.Delay(0); },
            OnViewAsync = (context) => { return Task.Delay(0); },
            OnRecieveMessageAsync = (context) => { return Task.Delay(0); },
        });

        app.UseStaticFiles();
        app.UseCookiePolicy();
        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
    }
}

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让我们再看看WeiXinServer类的定义：

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///

///

///

public class WeiXinServer : IWeiXinServerProvider

{

    /// <summary>
    /// <![CDATA[服务选项]]>
    /// </summary>
    public OAuth.WeiXinServerOptions ServerOptions { get; set; }

    /// <summary>
    ///
    /// </summary>
    public WeiXinServer()
    {

    }

    /// <summary>
    /// <![CDATA[运行服务]]>
    /// </summary>
    /// <param name="context"></param>
    /// <param name="configuration"></param>
    /// <param name="serverOptions"></param>
    /// <returns></returns>
    public async Task Run(HttpContext context, IConfiguration configuration)
    {
        #region 1、验证签名
        if (context.Request.Method.ToUpper() == "GET")
        {
            context.Response.ContentType = "text/plain;charset=utf-8";
            context.Response.StatusCode = 200;

            //1、验证签名
            if (WeiXin.Sdk.Common.Util.CheckSignature(context.Request.Query["nonce"],
                                                      context.Request.Query["timestamp"],
                                                      context.Request.Query["signature"],
                                                      configuration.GetSection("WeiXinOAuth")["Token"]))
            {
                await context.Response.WriteAsync(context.Request.Query["echostr"]);
                return;
            }
            await context.Response.WriteAsync("无效签名！");
            return;
        }
        #endregion  1、验证签名

        #region 2、接收微信消息
        await OnRecieve(context);//接收消息
        #endregion 2、接收微信消息
    }

    #region 虚方法
    /// <summary>
    /// <![CDATA[虚方法，接收消息后处理]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnRecieve(HttpContext context)
    {
        if (ServerOptions.OnRecieveAsync != null) return ServerOptions.OnRecieveAsync(context);
        string strRecieveBody = null;//接收消息
        using (System.IO.StreamReader streamReader = new System.IO.StreamReader(context.Request.Body))
        {
            strRecieveBody = streamReader.ReadToEndAsync().GetAwaiter().GetResult();
        }
        //序列化
        WeiXin.Sdk.Common.Serialization.XmlSerializer xmlSerializer = new WeiXin.Sdk.Common.Serialization.XmlSerializer(typeof(WeiXin.Sdk.Domain.Messages.Message));
        var recieve = (WeiXin.Sdk.Domain.Messages.Message)xmlSerializer.Deserialize(strRecieveBody);

        //事件消息
        if (recieve.MsgType == WeiXin.Sdk.Common.Constants.SystemConstants.MSG_TYPE.EVENT)
        {
            var weiXinContext = new WeiXinContext(recieve, context);
             var weiXinContext = new WeiXinContext(recieve, context);
             var actionName = recieve.Event.ToLower();
             actionName = actionName.First().ToString().ToUpper() + actionName.Substring(1);
             var action = this.GetType().GetMethod($"On{actionName}");
             if (action != null) return (Task)action.Invoke(this, new object[] { weiXinContext });

        }
        //被动接收消息
        else
        {
            return OnRecieveMessage(context);
        }
        return Task.Delay(0);
    }

    /// <summary>
    /// <![CDATA[被动接收消息]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnRecieveMessage(HttpContext context)
    {
        if (ServerOptions.OnRecieveMessageAsync != null) return ServerOptions.OnRecieveMessageAsync(context);
        return Task.Delay(0);
    }

    /// <summary>
    /// <![CDATA[扫描事件]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnScan(WeiXinContext context)
    {
        if (ServerOptions.OnScanAsync != null) return ServerOptions.OnScanAsync(context);
        return Task.Delay(0);
    }

    /// <summary>
    /// <![CDATA[关注事件]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnSubscribe(WeiXinContext context)
    {
        if (ServerOptions.OnSubscribeAsync != null) return ServerOptions.OnSubscribeAsync(context);
        return Task.Delay(0);
    }

    /// <summary>
    /// <![CDATA[取消关注]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnUnsubscribe(WeiXinContext context)
    {
        if (ServerOptions.OnUnsubscribeAsync != null) return ServerOptions.OnUnsubscribeAsync(context);
        return Task.Delay(0);
    }

    /// <summary>
    ///  <![CDATA[菜单点击]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnClick(WeiXinContext context)
    {
        if (ServerOptions.OnClickAsync != null) return ServerOptions.OnClickAsync(context);
        return Task.Delay(0);
    }

    /// <summary>
    /// <![CDATA[点击菜单链接]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnView(WeiXinContext context)
    {
        if (ServerOptions.OnViewAsync != null) return ServerOptions.OnViewAsync(context);
        return Task.Delay(0);
    }

    /// <summary>
    /// <![CDATA[上报地理位置]]>
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public virtual Task OnLocation(WeiXinContext context)
    {
        if (ServerOptions.OnLocationAsync != null) return ServerOptions.OnLocationAsync(context);
        return Task.Delay(0);
    }
    #endregion
}

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WeiXinServer类中还定义了时间消息的相关的虚方法，虚方法中，调用Options配置中定义的委托，这样，开发者一方面可以通过继承WeiXinServer或IWeiXinServerProvider接口，或通过设置Options属性，来灵活运用，开发者可根据自身需求，完成

对应业务逻辑即可。有了这些设计，我们可以轻松配置和完成微信消息的处理。

以上内容的全部代码，可以通过访问https://gitee.com/lichaoqiang/weixinmd 获取，不足之处，还望不吝赐教。