using Microsoft.AspNetCore.Mvc;using Microsoft.AspNetCore.Mvc.Filters;using Microsoft.AspNetCore.Mvc.Infrastructure;using Microsoft.AspNetCore.Mvc.Rendering;using Microsoft.AspNetCore.Mvc.ViewFeatures;using Microsoft.Extensions.DependencyInjection;using Microsoft.Extensions.Options;using System;using System.Collections.Generic;using System.IO;using System.Text;namespace NetCore.MVC{    /// 
    /// 访问静态页面过滤器    /// 
    [System.AttributeUsage(AttributeTargets.Method)]    public class StaticHtmlAttribute:ActionFilterAttribute    {        /// 
        /// 静态路由配置        /// 
        /// 静态路由地址        /// 数据id名称        public StaticHtmlAttribute(string url,string idfield="id")        {            Url = url;            idField = idfield;        }        /// 
        /// 静态文件路由        /// 
        public string Url { get; set; }        /// 
        /// 参数标识        /// 
        public string idField { get; set; }        /// 
        /// 是否清除文件标识        /// 
        private string RemoveClearKey = "remove";         /// 
        /// 静态文件根目录        /// 
        private string StaticFilesRootName        {            get            {                return ApplicationEnvironments.Site.BaseDirectory  + "html/";            }        }        public override void OnActionExecuting(ActionExecutingContext context)        {            string id = context.RouteData.Values.ContainsKey(idField) ? context.RouteData.Values[idField].ToString() : "";            if (string.IsNullOrEmpty(id) && context.HttpContext.Request.Query.ContainsKey(idField))            {                id = context.HttpContext.Request.Query[idField];            }            string filePath = StaticFilesRootName + string.Format(Url, id);            //判断文件是否存在            if (File.Exists(filePath))            {                if ( context.HttpContext.Request.Query.ContainsKey(RemoveClearKey))                {                    RemoveClearKey = context.HttpContext.Request.Query[RemoveClearKey];                    if (!string.IsNullOrWhiteSpace(RemoveClearKey))                    {                        File.Delete(filePath);                    }                }                else                {                    //如果存在，直接读取文件                    using (FileStream fs = File.Open(filePath, FileMode.Open))                    {                        using (StreamReader sr = new StreamReader(fs, Encoding.UTF8))                        {                            //通过contentresult返回文件内容                            ContentResult contentresult = new ContentResult();                            contentresult.Content = sr.ReadToEnd();                            contentresult.ContentType = "text/html";                            context.Result = contentresult;                        }                    }                }            }            base.OnActionExecuting(context);        }        public override void OnActionExecuted(ActionExecutedContext context)        {            CreateHtml(context);            base.OnActionExecuted(context);        }        /// 
        /// 生成html方法        /// 
        private void CreateHtml(ActionExecutedContext context)        {            IActionResult actionResult = context.Result;            if (actionResult is ViewResult)            {                ViewResult viewResult = actionResult as ViewResult;                //下面的代码就是执行这个ViewResult，并把结果的html内容放到一个StringBuiler对象中                var services = context.HttpContext.RequestServices;                var option = services.GetRequiredService
    
     
      >();                var executor = services.GetRequiredService
      
       
        >() as ViewResultExecutor    ?? throw new ArgumentNullException("executor");                var result = executor.FindView(context, viewResult);                result.EnsureSuccessful(originalLocations: null);                var view = result.View;                StringBuilder builder = new StringBuilder();                using (var writer = new StringWriter(builder))                {                    var viewContext = new ViewContext(                    context,                    view,                    viewResult.ViewData,                    viewResult.TempData,                    writer,                    option.Value.HtmlHelperOptions);                    view.RenderAsync(viewContext).GetAwaiter().GetResult();                    //这句一定要调用，否则内容就会是空的                    writer.Flush();                }                //按照规则生成静态文件名称                string id = context.RouteData.Values.ContainsKey(idField) ? context.RouteData.Values[idField].ToString() : "";                if (string.IsNullOrEmpty(id) && context.HttpContext.Request.Query.ContainsKey(idField))                {                    id = context.HttpContext.Request.Query[idField];                }                string filePath = StaticFilesRootName + string.Format(Url, id);                FileInfo info = new FileInfo(filePath);                if (!info.Exists)                {                    if (!info.Directory.Exists)                    {                        info.Directory.Create();                    }                }                //写入文件                using (FileStream fs = File.Open(filePath, FileMode.Create))                {                    using (StreamWriter sw = new StreamWriter(fs, Encoding.UTF8))                    {                        sw.Write(builder.ToString());                    }                }                //输出当前的结果                ContentResult contentresult = new ContentResult();                contentresult.Content = builder.ToString();                contentresult.ContentType = "text/html";                context.Result = contentresult;            }        }            }}