个人开发随笔

1. NET CORE 分布式缓存IDistributedCache

Microsoft.Extensions.Caching.Distributed.MemoryDistributedCache

Microsoft.Extensions.Caching.Redis.RedisCache

Microsoft.Extensions.Caching.SqlServer.SqlServerCache

Microsoft.Extensions.Caching.StackExchangeRedis.RedisCache

都继承了IDistributedCache，所以它们公用一套set ,get... 方法，可灵活按需切换
使用MemoryDistributedCache时则

services.AddDistributedMemoryCache();

使用StackExchangeRedis时则

services.RemoveAll(typeof(IDistributedCache));//移除其他所有IDistributedCache相关服务
services.AddStackExchangeRedisCache(opts =>
{
     opts.Configuration = config;
     opts.InstanceName = name;
});

2.asp.net core 5配置IIS报错 HTTP 错误 500.19 - Internal Server Error 

1. 检查你的IIS》"模块"》里是否 存在【AspNetCoreModuleV2】这个东西
2. 下载安装 dotnet-hosting-5.0.6-win.exe
3. 重启IIS

3.vue装包报错：run 'npm audit fix' or 'npm audit' for detail

1.  删除 node_modules 原包 和 删除package-lock.json。
2.  执行清除缓存命令：npm cache clean --force 
3.  全部重装包 npm install

4.VUE发布到IIS过程与注意事项

1. 先安装好IIS
2. 安装2个IIS相关的模块：

       重写模块，下载地址：URL Rewrite : The Official Microsoft IIS Site

       代理模块，下载地址：Application Request Routing : The Official Microsoft IIS Site

      下载之后直接点击文件运行下一步即可,安装好之后，IIS中就会多出2个功能模块：URL重写，Application Request Routing

     3. 将打包好的vue发布文件，复制到服务器，IIS新建网站

     4. IIS头节点，打开Application Request Routing，然后在页面右侧找到Server Proxy Settings按钮，点击进入设置；把Enable proxy前面打上勾，然后在页面右侧点击应用即可

     5. 选中自己创建好的OMS的前端网站，双击“URL重写”功能，进行相关重写配置，这里的配置其实最终会在网站的根节点创建一个Web.config文件

5. EF CORE 关联表删除的情况

1. 强关联-外键不可空  

public class ParentEntity
{
   public int Id { get;set;}
   public virtual ICollection Children { get; set; }
   ....
}

public class ChildrenEntity
{
   public int Id { get;set;}
   public int ParentId { get;set;}
   public virtual ParentEntity Parent { get; set; }
   ....
}
//关联关系配置
 builder.HasMany(m => m.ChildrenEntity).WithOne(a => a.ParentEntity).HasForeignKey(s => s.ParentId );
//执行Children.Remove(item),会实删这一条数据

    2. 弱关联-外键可空

public class ParentEntity
{
   public int Id { get;set;}
   public virtual ICollection Children { get; set; }
   ....
}

public class ChildrenEntity
{
   public int Id { get;set;}
   public virtual ParentEntity Parent { get; set; }//会生成可空的ParentId
   ....
}
//执行Children.Remove(item),不会实删这一条数据，会将这一条数据的 ParentId 置为空
//要想实删这一条数据,只能执行EF的Delete删除方法，手动删除

6.优秀架构

1. Vue.NetCore: 框架采用dotnetcore+vue+elementUI前后端分离；框架提供vue2、vue3版本 ；不一样的快速开发框架.http://www.volcore.xyz/

2. osharp: OSharp是个快速开发框架，但不是一个大而全的包罗万象的框架，严格的说，OSharp中什么都没有实现

7.Core自定义驼峰策略，首字母全部大写

public class UpperCamelCaseNamingStrategy : NamingStrategy
{
        protected override string ResolvePropertyName(string name)
        {
            if (char.IsLower(name,0))
            { 
                return string.Concat(name[0].ToString().ToUpper(), name.AsSpan(1));
            }
            return name;
        }
}

new JsonSerializerSettings()
{
    ContractResolver = new DefaultContractResolver() { 
        NamingStrategy = new UpperCamelCaseNamingStrategy()
    }
}

8. Core AuthorizationFilter

 public class ClaimAuthorizeAttribute : IAuthorizationFilter
    {
        private const string JwtClaimName = "name";
        private const string JwtClaimFullName = "full_name";
        private const string JwtClaimEmail = "email";
        private AuthorizationFilterContext context_;

        public void OnAuthorization(AuthorizationFilterContext context)
        {
            context_ = context;
            var res = context.HttpContext.AuthenticateAsync().Result;
            if (!res.Succeeded && !HasAllowAnonymous())//no token and no AllowAnonymous
            {
                context.Result = new JsonResult(new { Message = res?.Failure?.Message ?? "Unauthorized." });
                return;
            }

 var jwtHandler = new JwtSecurityTokenHandler();
                var tokenHeader = context_.HttpContext.Request.Headers["Authorization"].ToString().Replace("Bearer ", "");
               var jwtToken = jwtHandler.ReadJwtToken(tokenHeader);
 var name = jwtToken.Claims.FirstOrDefault(x => x.Type == JwtClaimName)?.Value;

            //var url = context.HttpContext.Request.Path.Value;
            //var heads = context.HttpContext.Request.Headers;
            //Microsoft.AspNetCore.Mvc.ObjectResult(res?.Failure?.Message) { StatusCode = 401 };
            //context.Result = new Microsoft.AspNetCore.Mvc.StatusCodeResult(401);
        }

private bool HasAllowAnonymous()
        {
            var filters_isAm = context_.Filters.Any(i => i is IAllowAnonymousFilter);
            if (filters_isAm)
            {
                return true;
            }
            var endpoint = context_.HttpContext.GetEndpoint();
            if (endpoint?.Metadata?.GetMetadata() != null)
            {
                return true;
            }
            return false;
        }
}

9. Core  ExceptionFilterAttribute

//IExceptionFilter 若是继承它就不能override 
public class ExceptionAttribute: ExceptionFilterAttribute
    {
        public bool IsDefaultCanelCase { get; set; } = true;

        public override void OnException(ExceptionContext context)
        { 
            var retData = new 
            {
                Message = context.Exception.Message,
            };
            var jsonResult = new JsonResult(retData, new JsonSerializerSettings
            {
                ContractResolver = IsDefaultCanelCase ? new DefaultContractResolver() : new CamelCasePropertyNamesContractResolver()
            });
            context.HttpContext.Response.StatusCode = 500;
            context.ExceptionHandled = true;
            context.Result = jsonResult;
        }
    }

10. Core Mappings 使用模式之一

       CreateMappings全部写在Model里，以接口实现的形式CreateMappings：

namespace WebApplication3.Models
{
    public interface IHaveMapping
    {
        void CreateMappings(IMapperConfigurationExpression configuration);
    }
}


namespace WebApplication3.Models
{
    public class TestModel: IHaveMapping
    {
        public string Id { get; set; }
        public string AssetId { get; set; }
        public int FilterNum { get; set; }
        public string FilterSize { get; set; }
        public string UserId { get; set; }

        public void CreateMappings(IMapperConfigurationExpression configuration)
        {
            configuration.CreateMap();
            configuration.CreateMap()
                .ForMember(dest => dest.UserId, source => source.MapFrom(s => s.CreateUserId));
        }
    }
}

Mappings stratup 注册：

public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllersWithViews();
            //services.AddAutoMapper11();
            services.AddAutoMapper(mapperConfigurationExpression =>
            {
                Type t_1 = typeof(IHaveMapping);
                //获取所有实现IHaveMapping接口的类的类型
                Type[] types = AppDomain.CurrentDomain.GetAssemblies().SelectMany(a => a.GetTypes().Where(t1 => t1.GetInterfaces().Contains(t_1))).ToArray();
                foreach (var t in types)
                {
                    object o = Activator.CreateInstance(t);//创建该类型的对象实例
                    var method = t.GetMethod("CreateMappings");//反射获取方法(实例方法)
                    method.Invoke(o, new object[] { mapperConfigurationExpression });//调用实例方法
                }
            });
        }

使用：

 public IActionResult Index()
        {
            var entity = new TestEntity() { Id = "12", AssetId = "10", FilterNum = 1, FilterSize = "120",CreateUserId = "4554" };
            var dto = _iMapper.Map(entity);
            return View();
        }

11. ActionFilter的试用

   全局Filter, 在filter中使用注入service:

public class ExampleActionFilter : IAsyncActionFilter
{
    private readonly IMemoryCache _memoryCache;
    public ExampleActionFilter(IMemoryCache memoryCache)
    {
        _memoryCache = memoryCache;
    }
 
    public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
    { 
//获取当前请求Action是否有某个属性
         var controllerActionDescriptor = context.ActionDescriptor as ControllerActionDescriptor;
            var myAttribute = controllerActionDescriptor.MethodInfo.GetCustomAttributes(typeof(MyAttribute), false).Cast().FirstOrDefault();
    }
}

//Starup注入
services.Configure(options =>
            {
                options.Filters.Add();
            });

  局部Filter，即继承Attribute，可以打在Action上给某个action使用

public class ExampleActionFilter : ActionFilterAttribute
    {
        public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
        {
            var svc = context.HttpContext.RequestServices;
            var cacheService = svc.GetService();

            var controllerActionDescriptor = context.ActionDescriptor as ControllerActionDescriptor;
            var myAttribute = controllerActionDescriptor.MethodInfo.GetCustomAttributes(typeof(MyAttribute), false).Cast().FirstOrDefault();
            
            await next();
        }
    }