从零开始搭建.NET Core 2.0 API(学习笔记一)

时间 2019-11-19

标签开始搭建 core 2.0 api 学习笔记繁體版

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　　从零开始搭建.NET Core 2.0 API(学习笔记一)app

1、 VS 2017 新建一个项目选择ASP.NET Core Web应用程序，再选择Web API,选择ASP.NET Core 2.0版本ide

2、添加API帮助页面 API项目添加 NuGet NSwag.AspNetCore 引用，而后在添加NSwag设置函数

运行项目 http://localhost:prot/swagger 便可打开帮助页。性能

public void Configure(IApplicationBuilder app, IHostingEnvironment env)

{
　　if (env.IsDevelopment())
　　{
　　　　app.UseDeveloperExceptionPage();
　　　　app.UseBrowserLink();
　　}
　　else
　　{
　　　　app.UseExceptionHandler("/Home/Error");
　　}

　　app.UseStaticFiles();


app.UseSwaggerUi(typeof(Startup).GetTypeInfo().Assembly, settings =>
{
　　settings.GeneratorSettings.DefaultPropertyNameHandling = PropertyNameHandling.CamelCase; });

app.UseMvc(route =>
{
　　route.MapRoute(name: "default", template: "{controller=Home}/{action=Get}/{id?}");
});

}

3、 Startup 类ConfigureServices方法中，添加配置中心初始化；配置中心统一管理配置，便于维护学习

public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            ConfigHelper.Init(Configuration["ConfigZookeeperAddress"], Configuration["ConfigNodePath"]);
            services.AddSingleton<ILogWrite, LogWrite>();

            services.AddMvc(options =>
            {
                options.Filters.Add<AuthorizationFilter>();
                options.Filters.Add<ExceptionFilter>();
                options.Filters.Add<PerformanceLogFilter>();
            });

            var builder = new ContainerBuilder();//实例化 AutoFac  容器            
            builder.Populate(services);

            // TODO: 这里添加其余须要注入类的注册

            ApplicationContainer = builder.Build();
            return new AutofacServiceProvider(ApplicationContainer);
        }

4、添加一个基础设置项目，添加一个日志接口 ILogWrite,一个记录日志实现类 LogWrite 在Startup 类ConfigureServices方法中添加日志 Iocui

由于日志拦截器和异常拦截器会用到日志记录须要注入因此日志在AddMvc()前面添加，Autofac配置不能在 AddMvc前面，因此这里用.NET Core的Ioc容器，后面Autofac会接管容器。this

services.AddSingleton<ILogWrite, LogWrite>();

5、filter 添加三个类分别是spa

　　a AuthorizationFilter 权限过滤器pwa

　　b ExceptionFilter 异常过滤器日志

　　c PerformanceLogFilter 性能日志过滤器

　　ExceptionFilter 、PerformanceLogFilter 分别定义构造函数，注入日志依赖。

public ExceptionFilter(ILogWrite logWrite)
{
　　_logWrite = logWrite;
}

public PerformanceLogFilter(ILogWrite logWrite)
{
　　_logWrite = logWrite;
}

过滤器必须添加在 Startup类ConfigureServices的services.AddMvc()中

services.AddMvc(options =>
{
    options.Filters.Add<AuthorizationFilter>();
    options.Filters.Add<ExceptionFilter>();
    options.Filters.Add<PerformanceLogFilter>();
});

6、Action参数读取，为了在异常过滤器、性能日志过滤器中，读取参数须要在权限过滤器中添加下面两行代码

public class AuthorizationFilter : IAuthorizationFilter
{
　　public void OnAuthorization(AuthorizationFilterContext context)
　　{
　　　　HttpRequest request = context.HttpContext.Request;
　　　　request.EnableRewind(); 　　　　request.Body.Position = 0;
　　}
}

7、性能日志过滤器 PerformanceLogFilter 继承 IActionFilter，实现两个接口

　　　　OnActionExecuting 在调用操做方法以前发生
　　　　OnActionExecuted 在调用操做方法以后发生
　　a 在方法 OnActionExecuting中实例化一个 Stopwatch 用于记录方法开支执行时间
　　把Stopwatch 实力加入 HttpContext.Items 中，便于在 OnActionExecuted 获取。

　　b 读取Action请求参数, 放入 HttpContext.Items 中, 不知道为何OnActionExecuted 去不到参数

　　　　　/// <summary>
        /// 在调用操做方法以前发生。
        /// </summary>
        /// <param name="context"></param>
        public void OnActionExecuting(ActionExecutingContext context)
        {
　　　　　　　//
            if (SkipLogging(context)) return;

            var watch = new Stopwatch();
            context.HttpContext.Items[ConfigHelper.HttpRequestStopWatcher] = watch;
            var paramenters = context.ActionArguments.Count==0?string.Empty:context.ActionArguments.Serialize();
            context.HttpContext.Items[ConfigHelper.FilterActionArguments] = paramenters; watch.Start();
        }

OnActionExecuting 中增长了性能日志开关，若是关闭直接返回，不建立Stopwatch,
在OnActionExecuted中回去到的Stopwatch是null 则直接返回（也能够用性能日志开关作判断），不处理后续。
若是Controll、Action添加了NoLog特性，则不记录性能日志

        private static bool SkipLogging(ActionExecutingContext actionContext)
        {
            if (!ConfigHelper.IsPerformanceLog) return true;
            return actionContext.ActionDescriptor.GetType().GetCustomAttributes(typeof(NoLogAttribute), false).Any() ||
                   actionContext.Controller.GetType().GetCustomAttributes(typeof(NoLogAttribute), false).Any();
        }

    　　/// <summary>
    　　/// 忽略性能日志记录特性
    　　/// </summary>
    　　[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, Inherited = true)]
    　　public class NoLogAttribute : Attribute
    　　{
    　　}

8、异常过滤器

　　 /// <summary>
    /// 异常拦截器
    /// </summary>
    public class ExceptionFilter : IExceptionFilter
    {
        ILogWrite _logWrite;
        public ExceptionFilter(ILogWrite logWrite)
        {
            _logWrite = logWrite;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="actionExecutedContext"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public void OnException(ExceptionContext context)
        {
            BizResult<bool> biz;

            var paramenters = context.HttpContext.Items[ConfigHelper.FilterActionArguments].ToString();
            try
            {
                biz = new BizResult<bool>(false, (int)B2CBizCode.Exception, context.Exception.Message);

                if (context.Exception.InnerException != null)
                    biz.SysMessage += ":" + context.Exception.InnerException.Message;

                if (ConfigHelper.IsPerformanceLog)
                {
                    var watch = context.HttpContext.Items[ConfigHelper.HttpRequestStopWatcher] as Stopwatch;
                    watch?.Stop();

                    var name = context.ActionDescriptor.GetType().GetProperty("ActionName").GetValue(context.ActionDescriptor).ToString();

                    _logWrite.InfoAsync(new 
                    {
                        CreateTime = DateTime.Now,
                        Method = name,
                        TimeSpan = watch.Elapsed,
                        IsSuccess = false,
                        Content = paramenters,
                        Code = ((B2CBizCode)biz.BusinessCode).ToString(),
                        Message = biz.BusinessMessage
                    }.Serialize());
                }
            }
            catch (Exception ex)
            {
                biz = new BizResult<bool>(false, (int)B2CBizCode.Exception, ex.Message);
            }
            context.Result = new ApplicationErrorResult(biz);

            _logWrite?.ErrorAsync($"连接访问出错：{context.HttpContext.Request.Path}", context.HttpContext.Request.Method, this.GetType().Name, context.Exception, paramenters);
            return;
        }
    }

    public class ApplicationErrorResult : ObjectResult
    {
        public ApplicationErrorResult(object value) : base(value)
        {
            StatusCode = (int)HttpStatusCode.InternalServerError;
        }
    }

九、添加Autofac，Autofac比.NET Core自带的 Ioc更好用。 NuGetAPI 项目中添加Autofac.Configuration、Autofac.Extensions.DependencyInjection 两个引用而后 ConfigureServices方法中添加Ioc容器

 　　　　public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            ConfigHelper.Init(Configuration["ConfigZookeeperAddress"], Configuration["ConfigNodePath"]);
            services.AddSingleton<ILogWrite, LogWrite>();

            services.AddMvc(options =>
            {
                options.Filters.Add<AuthorizationFilter>();
                options.Filters.Add<ExceptionFilter>();
                options.Filters.Add<PerformanceLogFilter>();
            });

            var builder = new ContainerBuilder();//实例化 AutoFac  容器            
            builder.Populate(services);

            // TODO: 这里添加其余须要注入类的注册

            ApplicationContainer = builder.Build();
            return new AutofacServiceProvider(ApplicationContainer);
        }

至此.NET Core API的拦截器、配置管理、日志、Ioc 设置已完成。

public IServiceProvider ConfigureServices(IServiceCollection services) { ConfigHelper.Init(Configuration["ConfigZookeeperAddress"], Configuration["ConfigNodePath"]); services.AddSingleton<ILogWrite, LogWrite>(); services.AddMvc(options => { options.Filters.Add<AuthorizationFilter>(); options.Filters.Add<ExceptionFilter>(); options.Filters.Add<PerformanceLogFilter>(); }); var builder = new ContainerBuilder();//实例化 AutoFac 容器 builder.Populate(services); // TODO: 这里添加其余须要注入类的注册 ApplicationContainer = builder.Build(); return new AutofacServiceProvider(ApplicationContainer); }