?????????????????????????????????????????????????????????漰?????????????????????????????????????Configuration????????????????ConfigurationProvider????????“?м???”??ConfigurationBuilder???????????????????????????????????????????????????????????????????б??????????????????????????????????????????
?????????????????
???????????????в????????????????????????????????????????????????????????????????Configuration???????????????????????????????????λ????ν??????t??ж??????????????????????????????????????????????????????????????y????????????????????????????????????????????????????????м?????????????????????

?????????
????????????????Configuration?????????????????????????????????Configuration?????API????????????????????е?Configuration???????????????????????????????????????????????ν??????????????????????????????????????????Configuration????????????????????????洢????????У????????????????????????y?????????????????????????????????????????????????????FormatSettings???????????????t????????????????????
????????
???????ò????????????????????????ú??????????????????????????????????????????????????????????????????????????????????????????????????FormatSettings??????????????????μ??????XML??JSON???????????????á?
????XML:
1: <Format>
2:   <DateTime>
3:     <LongDatePattern>dddd?? MMMM d?? yyyy</LongDatePattern>
4:     <LongTimePattern>h:mm:ss tt</LongTimePattern>
5:     <ShortDatePattern>M/d/yyyy</ShortDatePattern>
6:     <ShortTimePattern>h:mm tt</ShortTimePattern>
7:   </DateTime>
8:   <CurrencyDecimal>
9:     <Digits>2</Digits>
10:     <Symbol>$</Symbol>
11:   </CurrencyDecimal>
12: </Format>
????JSON:
1: {
2:   "format": {
3:     "dateTime": {
4:       "longDatePattern"    : "dddd?? MMMM d?? yyyy"??
5:       "longTimePattern"    : "h:mm:ss tt"??
6:       "shortDatePattern"    : "M/d/yyyy"??
7:       "shortTimePattern"    : "h:mm tt"
8:     }??
9:     "currencyDecimal": {
10:       "digits": "2"??
11:       "symbol": "$"
12:     }
13:   }
14: }
?????????
????table???????????????????????????????????????????н?????????????????????????????????????????Configuration?????????????????????????????м???????????????????????????????????????????????FormatSettings????????????????y????????±?????????????

?????????
????transfer???????????????????в????????????????Configuration???????????Configuration?????????????????????????????????????????????????????????????????????????????????????????У???????????????????????????ConfigurationProvider??????????????????????????????????????????????????ConfigurationBuilder????Configuration?????????????????????????????????????

????????Configuration
?????????????????????????????????Configuratin??ConfigurationProvider??ConfigurationBuilder???????????????????????????????????????????????????????????????????????????????Configuration???????2???????Configuration????????????IConfiguration????????y???????“Microsoft.Extensions.Configuration”????????￡????δ???????????????漰????????????????????????????????????
????1: public interface IConfiguration
????2: {
????3:     IEnumerable<IConfigurationSection>     GetChildren();
????4:     IConfigurationSection                  GetSection(string key);
????5:     IChangeToken                           GetReloadToken();
????6:
????7:     string this[string key] { get; set; }
????8: }
???????t?????????????????Configuration????????????????????y????????????????????????y????????????????Configuration???????????????y???Configuration?????????в??????????????????????ò??????????????????????????????????Configuration??????????IConfigurationRoot?????????????IConfigurationSection????????????Configuration???????????????IConfiguration????????????????????????????????ConfigurationRoot????????ConfigurationSection???ɡ?

????ConfigurationRoot
??????????????????IConfigurationRoot??????????????????ConfigurationRoot????????????????????IConfigurationRoot????????????????Reload????????????????????????ConfigurationRoot?????????????????????????????????????????????????????????????????????????????
????1: public interface IConfigurationRoot : IConfiguration
????2: {
????3:     void Reload();
????4: }
????ConfigurationSection
??????????????????IConfigurationSection??????????????????ConfigurationSection?????ConfigurationSection??????????????????????y??IConfigurationSection????????????????????????Key??????????“???”???y????????????????Path????????????????·??????·????ConfigurationSection??Key??????????e???????????Path??Key????????????????y??????????????е?λ?á?
????1: public interface IConfigurationSection : IConfiguration
????2: {
????3:     string Path { get; }
????4:     string Key { get; }
????5:     string Value { get; set; }
????6: }
????IConfigurationSection??Value?????????y??????????????￡???????????????????ConfigurationSection??????????????????????ConfigurationSection?????????????????????????????????????y????????????????Value?????Null???????????????Value???????????????????????д???
???????ConfigurationRoot??ConfigurationSection???л????????????????????????????????IConfiguration?е?????????GetChildren????????????????????y??ConfigurationSection????????????????GetSection??????????Key????????ConfigurationSection??????GetSection??????е???????????????????ConfigurationSection??Path???????????????ConfigurationSection?????·????????????????÷????????????????????????y??·??????????????????????μ???????y??
1: Dictionary<string?? string> source = new Dictionary<string?? string>
2: {
3:     ["A:B:C"] = "ABC"
4: };
5: IConfiguration root = new ConfigurationBuilder()
6:         .Add(new MemoryConfigurationProvider(source))
7:         .Build();
8:
9: IConfigurationSection section1 = root.GetSection("A:B:C");
10: IConfigurationSection section2 = root.GetSection("A:B").GetSection("C");
11: IConfigurationSection section3 = root.GetSection("A").GetSection("B:C");
12:
13: Debug.Assert(section1.Value == section2.Value && section2.Value == section3.Value);
14: Debug.Assert(!ReferenceEquals(section1?? section2) && !ReferenceEquals(section2?? section3));
15: Debug.Assert(null == root.GetSection(Guid.NewGuid().ToString()));
??????????????????????????????????????GetSection????????????·???“Format:DateTime:LongDatePattern”??ConfigurationSection????????δ????????????????????????????????ConfigurationSection???????????????????????????????????????????????仰????????????GetSection???????????????????????????????????·?????????y????????????????μ?ConfigurationSection????
????IConfiguration??????????????????????????????y??Key????????????y??·???????????y????????????????е????????????GetSection?????????μ??????????ConfigurationSection????????????Value???????????????в????????????y????????????Null?????????????