Asp.NetCore实战(干货)

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原作者: [db:作者] 来自: [db:来源] 收藏邀请

序言

使用.NET Core，团队可以更容易专注的在.net core上工作。比如核心类库（如System.Collections）的更改仍然需要与.NET Framework相同的活力，但是ASP.NET Core或Entity Framework Core可以更轻松地进行实质性更改，而不受向后兼容性的限制。.NET Core借鉴了.NET Framework的最佳实践，并将软件工程的最新进展结合在一起。

寒暄、扯淡已经完毕，，，下面是我最近时间对.Net Core整理的相关知识，觉得这些在项目中是最基础且最会应用到的，，，，不喜欢扯理论，直接撸码：

1、浅谈Startup类

2、自定义路由

3、跨域设置

4、自定义读取配置文件信息

5、程序集批量依赖注入

6、使用NLog写入文件日志

7、使用NLog写入数据库日志

8、Nlog标签解读

9、启用Session

10、json数据，自定义日期格式

11、json数据，string类型字段返回为null时默认返回空字符串

12、Json数据，返回字段同实体字段大小写一致

一、浅谈Startup类

在ASP.NET Core应用程序中，使用一个按约定Startup命名的类Startup，在Program.cs中使用WebHostBuilderExtensions UseStartup <TStartup>方法指定类，但通常使用系统默认的startup，可以通过startup的构造函数进行依赖注入，startup类中必须包含Configure方法同时可以根据实际情况添加ConfigureServices方法，这两个方法均在应用程序运行时被调用。Startup 类的执行顺序：构造 -> configureServices ->configure

ConfigureServices方法：主要用于服务配置，比如依赖注入(DI)的配置，使用时该方法必须在Configure方法之前

Configure方法：用于应用程序响应HTTP请求，通过向IApplicationBuilder实例添加中间件组件来配置请求管道

二、自定义路由

在Startup类的Configure方法配置

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            #region 自定义路由配置
            app.UseMvc(routes =>
            {
                // 自定义路由
                routes.MapRoute(
                  name: "default1",
                  template: "api/{controller}/{action}/{id?}",
                  defaults: new { controller = "Values", action = "Index" });
                // 默认路由
                routes.MapRoute(
                   name: "default",
                   template: "{controller}/{action}/{id?}",
                   defaults: new { controller = "Values", action = "Index" });
            });
            #endregion
        }

三、跨域设置

在Startup类的ConfigureServices方法配置

public void ConfigureServices(IServiceCollection services)
        {
            #region 跨域设置
            services.AddCors(options =>
            {
                options.AddPolicy("AppDomain", builder =>
                {
                    builder.AllowAnyOrigin() // Allow access to any source from the host
                    .AllowAnyMethod()        // Ensures that the policy allows any method
                    .AllowAnyHeader()        // Ensures that the policy allows any header
                    .AllowCredentials();     // Specify the processing of cookie
                });
            });
            #endregion

            services.AddMvc();
        }

其中“AppDomain”这个名字是自定义的，大家可以根据自己的喜好定义不同的名字，配置完成之后，在控制器上面添加[EnableCors("AppDomain")]特性即可，如果要实现全局的跨域设置，可以在Configure方法里面配置app.UseCors("AppDomain")，即能实现全局的跨域设置

四、自定义读取配置文件信息

这里是写的一个公共方法去读取配置文件appsettings.json

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using System.IO;

public class JsonConfigurationHelper
    {
        public static T GetAppSettings<T>(string key,string path= "appsettings.json") where T : class, new()
        {
            var currentClassDir = Directory.GetCurrentDirectory();
            IConfiguration config = new ConfigurationBuilder()
                .SetBasePath(currentClassDir)
                .Add(new JsonConfigurationSource { Path = path, Optional = false, ReloadOnChange = true })
                .Build();
            var appconfig = new ServiceCollection()
                .AddOptions()
                .Configure<T>(config.GetSection(key))
                .BuildServiceProvider()
                .GetService<IOptions<T>>()
                .Value;
            return appconfig;
        }
    }

/// <summary>
        /// 读取配置文件
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public dynamic JsonConfig()
        {
            var jsonStr = JsonConfigurationHelper.GetAppSettings<ConfigDTO>("config");
            return Ok(jsonStr);
        }

        /// <summary>
        /// 实体类
        /// </summary>
        public class ConfigDTO
        {
            public dynamic name { get; set; }
        }

{
  "config": {
    "name": "Core.Api"
  }
}

截图看效果

五、程序集批量依赖注入

我们都知道依赖注入主要是为了方便解耦，解除应用程序之间的依赖关系，在我看来DI、IOC这两者差不多是一样的，DI是从应用程序的角度而IOC是从容器的角度，它们主要是对同一件事情的不同角度的描述。然而，，，，，，当我们项目业务比较多的时候，如果要实现多个业务的注入，通常方法是手动一个个的添加注入，这样可能有点太繁琐，所以就想到了利用反射实现批量注入，，，，，，

方法一

帮助类

public class RuntimeHelper
    {
        /// <summary>
        /// 获取项目程序集，排除所有的系统程序集(Microsoft.***、System.***等)、Nuget下载包
        /// </summary>
        /// <returns></returns>
        public static IList<Assembly> GetAllAssemblies()
        {
            var list = new List<Assembly>();
            var deps = DependencyContext.Default;
            var libs = deps.CompileLibraries.Where(lib => !lib.Serviceable && lib.Type != "package");//排除所有的系统程序集、Nuget下载包
            foreach (var lib in libs)
            {
                try
                {
                    var assembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(lib.Name));
                    list.Add(assembly);
                }
                catch (Exception)
                {
                    // ignored
                }
            }
            return list;
        }

        public static Assembly GetAssembly(string assemblyName)
        {
            return GetAllAssemblies().FirstOrDefault(assembly => assembly.FullName.Contains(assemblyName));
        }

        public static IList<Type> GetAllTypes()
        {
            var list = new List<Type>();
            foreach (var assembly in GetAllAssemblies())
            {
                var typeInfos = assembly.DefinedTypes;
                foreach (var typeInfo in typeInfos)
                {
                    list.Add(typeInfo.AsType());
                }
            }
            return list;
        }

        public static IList<Type> GetTypesByAssembly(string assemblyName)
        {
            var list = new List<Type>();
            var assembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(assemblyName));
            var typeInfos = assembly.DefinedTypes;
            foreach (var typeInfo in typeInfos)
            {
                list.Add(typeInfo.AsType());
            }
            return list;
        }

        public static Type GetImplementType(string typeName, Type baseInterfaceType)
        {
            return GetAllTypes().FirstOrDefault(t =>
            {
                if (t.Name == typeName &&
                    t.GetTypeInfo().GetInterfaces().Any(b => b.Name == baseInterfaceType.Name))
                {
                    var typeInfo = t.GetTypeInfo();
                    return typeInfo.IsClass && !typeInfo.IsAbstract && !typeInfo.IsGenericType;
                }
                return false;
            });
        }
    }

public static class ServiceExtension
    {
        /// <summary>
        /// 用DI批量注入接口程序集中对应的实现类。
        /// </summary>
        /// <param name="service"></param>
        /// <param name="interfaceAssemblyName"></param>
        /// <returns></returns>
        public static IServiceCollection RegisterAssembly(this IServiceCollection service, string interfaceAssemblyName)
        {
            if (service == null)
                throw new ArgumentNullException(nameof(service));
            if (string.IsNullOrEmpty(interfaceAssemblyName))
                throw new ArgumentNullException(nameof(interfaceAssemblyName));

            var assembly = RuntimeHelper.GetAssembly(interfaceAssemblyName);
            if (assembly == null)
            {
                throw new DllNotFoundException($"the dll \"{interfaceAssemblyName}\" not be found");
            }

            //过滤掉非接口及泛型接口
            var types = assembly.GetTypes().Where(t => t.GetTypeInfo().IsInterface && !t.GetTypeInfo().IsGenericType);

            foreach (var type in types)
            {
                var implementTypeName = type.Name.Substring(1);
                var implementType = RuntimeHelper.GetImplementType(implementTypeName, type);
                if (implementType != null)
                    service.AddSingleton(type, implementType);
            }
            return service;
        }

        /// <summary>
        /// 用DI批量注入接口程序集中对应的实现类。
        /// </summary>
        /// <param name="service"></param>
        /// <param name="interfaceAssemblyName">接口程序集的名称（不包含文件扩展名）</param>
        /// <param name="implementAssemblyName">实现程序集的名称（不包含文件扩展名）</param>
        /// <returns></returns>
        public static IServiceCollection RegisterAssembly(this IServiceCollection service, string interfaceAssemblyName, string implementAssemblyName)
        {
            if (service == null)
                throw new ArgumentNullException(nameof(service));
            if (string.IsNullOrEmpty(interfaceAssemblyName))
                throw new ArgumentNullException(nameof(interfaceAssemblyName));
            if (string.IsNullOrEmpty(implementAssemblyName))
                throw new ArgumentNullException(nameof(implementAssemblyName));

            var interfaceAssembly = RuntimeHelper.GetAssembly(interfaceAssemblyName);
            if (interfaceAssembly == null)
            {
                throw new DllNotFoundException($"the dll \"{interfaceAssemblyName}\" not be found");
            }

            var implementAssembly = RuntimeHelper.GetAssembly(implementAssemblyName);
            if (implementAssembly == null)
            {
                throw new DllNotFoundException($"the dll \"{implementAssemblyName}\" not be found");
            }

            //过滤掉非接口及泛型接口
            var types = interfaceAssembly.GetTypes().Where(t => t.GetTypeInfo().IsInterface && !t.GetTypeInfo().IsGenericType);

            foreach (var type in types)
            {
                //过滤掉抽象类、泛型类以及非class
                var implementType = implementAssembly.DefinedTypes
                    .FirstOrDefault(t => t.IsClass && !t.IsAbstract && !t.IsGenericType &&
                                         t.GetInterfaces().Any(b => b.Name == type.Name));
                if (implementType != null)
                {
                    service.AddSingleton(type, implementType.AsType());
                }
            }

            return service;
        }
    }

在Startupl类的ConfigureServices方法中添加

// This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            #region 程序集批量依赖注入
            services.RegisterAssembly("Core.BLL");
            #endregion

            services.AddMvc();
        }

调用(Ps:Core.BLL这个类库里面分别有一个接口IAccountService和一个类AccountService，AccountService类去继承接口IAccountService并实现接口里面的方法)

public interface IAccountService
    {
        int GetLst();
    }

public class AccountService: IAccountService
    {
        public int GetLst()
        {
            return 1;
        }
    }

public class ValuesController : Controller
    {
        private readonly IAccountService _accountService;
        public ValuesController(IAccountService accountService)
        {
            _accountService = accountService;
        }

        [HttpGet]
        public dynamic GetAccount()
        {
            var result = this._accountService.GetLst();
            return Ok();
        }
}

方法二

public static class InjectionExtension
    {
        /// <summary>
        /// 批量注入接口程序集中对应的实现类(接口和实现类在同一个程序集时)
        /// </summary>
        /// <param name="services">services</param>
        /// <param name="assemblyName">程序集名称</param>
        public static void BatchAddScoped(this IServiceCollection services, string assemblyName)
        {
            if (services == null)
                throw new ArgumentNullException(nameof(services));
            if (assemblyName == null)
                throw new ArgumentNullException(nameof(assemblyName));

            // 排除所有的系统程序集，Nuget下载包
            var libs = DependencyContext.Default.CompileLibraries.Where(lib => !lib.Serviceable && lib.Type != "package");
            var serviceLib = libs.Where(c => c.Name.Contains(assemblyName)).FirstOrDefault();
            var assembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(serviceLib.Name));
            var serviceClassList = assembly.GetTypes().Where(x=>x.IsInterface).ToList();
            foreach (var item in serviceClassList)
            {
                var implementName = item.Name.Substring(1,item.Name.Length-1);
                var implementType= assembly.GetTypes().Where(c => c.IsClass && c.Name == implementName).FirstOrDefault();
                if (implementType == null) continue;
                services.AddScoped(item, implementType);
            }
        }

        /// <summary>
        /// 批量注入接口程序集中对应的实现类(接口和实现类在不同程序集时)
        /// </summary>
        /// <param name="services"></param>
        /// <param name="interfaceAssemblyName"></param>
        /// <param name="implementAssemblyName"></param>
        public static void BatchAddScoped(this IServiceCollection services, string interfaceAssemblyName, string implementAssemblyName)
        {
            if (services == null)
                throw new ArgumentNullException(nameof(services));
            if (string.IsNullOrEmpty(interfaceAssemblyName))
                throw new ArgumentNullException(nameof(interfaceAssemblyName));
            if (string.IsNullOrEmpty(implementAssemblyName))
                throw new ArgumentNullException(nameof(implementAssemblyName));

            // 排除所有的系统程序集，Nuget下载包
            var libs = DependencyContext.Default.CompileLibraries.Where(lib => !lib.Serviceable && lib.Type != "package");

            var serviceInterfaceLib = libs.Where(c => c.Name.Contains(interfaceAssemblyName)).FirstOrDefault();
            var interfaceAssembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(serviceInterfaceLib.Name));
            // 过滤非接口
            var serviceInterfaceList = interfaceAssembly.GetTypes().Where(x => x.IsInterface).ToList();
            
            var serviceImplementLib = libs.Where(c => c.Name.Contains(implementAssemblyName)).FirstOrDefault();
            var implementAssembly = AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(serviceImplementLib.Name));
            // 过滤抽象类、泛型类以及非class
            foreach (var item in serviceInterfaceList)
            {
                var implementName = item.Name.Substring(1, item.Name.Length - 1);
                var implementType = implementAssembly.GetTypes().Where(c => c.IsClass && c.Name == implementName).FirstOrDefault();
                if (implementType == null) continue;
                services.AddScoped(item, implementType);
            }
        }
    }

public void ConfigureServices(IServiceCollection services)
        {
            #region 程序集批量依赖注入
            services.BatchAddScoped("Core.BLL");  // 接口和实现类在同一个程序集
            services.BatchAddScoped("Core.Model", "Core.BLL");// 接口和实现类在不同程序集
            #endregion
        }

六、使用NLog写入文件日志

新建配置文件命名为Nlog.config

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <targets>
    
<!--写入文件-->
    <target
     xsi:type="File"
     name="DebugFile"
     fileName="Logs\Debug\${shortdate}.log"
     layout="日志时间：${longdate}${newline}日志来源：${callsite}${newline}日志级别：${uppercase:${level}}${newline}消息内容：${message}${newline}异常信息：${exception}${newline}==============================================================${newline}" >
    </target>
    <target 
      xsi:type="File" 
      name="InfoFile" 
      fileName="Logs\Info\${shortdate}.log"
      layout="日志时间：${longdate}${newline}日志来源：${callsite}${newline}日志级别：${uppercase:${level}}${newline}消息内容：${message}${newline}异常信息：${exception}${newline}==============================================================${newline}" >
    </target>
    <target 
      xsi:type="File" 
      name="ErrorFile" 
      fileName="Logs\Error\${shortdate}.log"
      layout="日志时间：${longdate}${newline}日志来源：${callsite}${newline}日志级别：${uppercase:${level}}${newline}消息内容：${message}${newline}异常信息：${exception}${newline}==============================================================${newline}" >
    </target>    

  <rules>
    <logger name="FileLogger" minlevel="Debug" maxLevel="Debug" writeTo="DebugFile" />
    <logger name="FileLogger" minlevel="Info" maxLevel="Info" writeTo="InfoFile" />
    <logger name="FileLogger" minlevel="Error" maxLevel="Error" writeTo="ErrorFile" />
  </rules>
</nlog>

在Startup类Configure方法中添加配置

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            #region NLog配置
            loggerFactory.AddNLog(); // 添加NLog
            loggerFactory.ConfigureNLog($"{Directory.GetCurrentDirectory()}\\Nlog.config"); // 添加Nlog.config配置文件
            loggerFactory.AddDebug();
            #endregion
        }

写入日志到文件

View Code

七、使用NLog写入数据库日志

添加依赖项：Microsoft.Extensions.Logging和NLog.Extensions.Logging

新建配置文件命名为Nlog.config

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <targets>

    <!--写入数据库-->
    <target xsi:type="Database" name="Database"
            connectionString="Data Source=.;Initial Catalog=MyDb;Persist Security Info=True;User ID=sa;Password=123456"
            commandText="insert into NLog_Log([CreateOn],[Origin],[LogLevel], [Message], [Exception],[StackTrace],[Desc]) values (getdate(), @origin, @logLevel, @message,@exception, @stackTrace,@desc)">
      
      <!--日志来源-->
      <parameter name="@origin" layout="${callsite}"/>
      <!--日志等级-->
      <parameter name="@logLevel" layout="${level}"/>
      <!--日志消息-->
      <parameter name="@message" layout="${message}"/>
      <!--异常信息-->
      <parameter name="@exception" layout="${exception}" />
      <!--堆栈信息-->
      <parameter name="@stackTrace" layout="${stacktrace}"/>
      <!--自定义消息内容-->
      <parameter name="@desc" layout="${event-context:item=Desc}"/>
    </target>
  </targets>

  <rules>
    <logger name="DbLogger" levels="Trace,Debug,Info,Error"  writeTo="Database"/>
  </rules>
</nlog>

同第六项代码一样，也是在Configure方法设置，写入日志到数据库

/// <summary>
        /// 将日志写入数据库
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public dynamic WriteLogToDb()
        {
            Logger _dblogger = LogManager.GetLogger("DbLogger");
            LogEventInfo ei = new LogEventInfo();
            ei.Properties["Desc"] = "我是自定义消息";
            _dblogger.Info(ei);
            _dblogger.Debug(ei);
            _dblogger.Trace(ei);
            return Ok();
        }

USE [MyDb]
GO

/****** Object:  Table [dbo].[NLog_Log]    Script Date: 08/09/2018 17:13:20 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[NLog_Log](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [Origin] [nvarchar](500) NULL,
    [LogLevel] [nvarchar](500) NULL,
    [Message] [nvarchar](500) NULL,
    [Desc] [nvarchar](500) NULL,
    [Exception] [nvarchar](500) NULL,
    [StackTrace] [nvarchar](500) NULL,
    [CreateOn] [datetime] NULL
) ON [PRIMARY]

GO