在.Net Framework中，配置文件一般采用的是XML格式的，.NET Framework提供了专门的ConfigurationManager来读取配置文件的内容，.net core中推荐使用json格式的配置文件，那么在.net core中该如何读取json文件呢？

1、在Startup类中读取json配置文件

在Startup加入配置

 var configurationBuilder = new ConfigurationBuilder();
 var builder = configurationBuilder.AddJsonFile("UploadFile/GetCourts.json", false, true).AddJsonFile("UploadFile/Queryareadatalevelall.json", false, true);
 var Courtlist = new Courtlist();
 builder.Build().GetSection("Courtsmodel").Bind(Courtlist);
 services.AddSingleton(Courtlist);

构造函数注入读取

 private readonly Courtlist _Courtlist;
 private readonly AreaRootobjectlist _AreaRootobjectlist;
 public DmsCacheService(
 AreaRootobjectlist AreaRootobjectlist,
 Courtlist Courtlist,
 ILogger<DmsCacheService> logger,
 AccessAddressDto accessAddress,
 IEasyCachingProvider provider,
 IJudgeBannedWordsService judgeBannedWordsService,
 IJudgeService judgeService,
 IMapper mapper)
 {
 this.provider = provider;
 this.judgeService = judgeService;
 this.judgeBannedWordsService = judgeBannedWordsService;
 this.mapper = mapper;
 this.accessAddress = accessAddress;
 this.logger = logger;
 _Courtlist = Courtlist;
 _AreaRootobjectlist = AreaRootobjectlist;
 }
 public List<Court> GetCourts()
 {
return _Courtlist.Courtlists;
 }

定义读取方法

 private T GetDataByLocal<T>(string jsonfileName)
 {
 var res = this.provider.Get<T>(jsonfileName);
if (res.HasValue)
 {
return res.Value;
 }
 var filePath = $"/UploadFile/";
 string applicationRoot = AppContext.BaseDirectory;
 var provider = new PhysicalFileProvider(applicationRoot);
 var completeFilePath = Path.Combine(filePath, jsonfileName);
if (!System.IO.File.Exists(AppContext.BaseDirectory + completeFilePath))
 {
 throw new Exception("文件不存在");
 }
 var formFile = provider.GetFileInfo(completeFilePath);
 var stream = formFile.CreateReadStream();
 Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
 Encoding encoding = Encoding.GetEncoding("gb2312");
 using var reader = new StreamReader(stream, encoding);
 string rs = reader.ReadToEnd();
 var result = JsonConvert.DeserializeObject<T>(rs);
 this.provider.Set<T>(jsonfileName, result, this.GetExpiredTimeSpan());
return result;
 }

传入文件名进行读取

 public List<CaseCodeType> GetCaseCodes()
 {
return this.GetDataByLocal<List<CaseCodeType>>("GetCaseCodes.json");
 }