.net core 读取、修改配置文件appsettings.json

.net core 设置读取json配置文件 appsettings.json

startup.cs 中

    public class startup
    {
        public startup(ihostingenvironment env)
        {
            configuration = new configurationbuilder()
                .setbasepath(env.contentrootpath)
                .addjsonfile("appsettings.json", optional: true, reloadonchange: true)
                .addjsonfile($"appsettings.{env.environmentname}.json", optional: true, reloadonchange: true)  //增加环境配置文件，新建项目默认有
                .addenvironmentvariables()
                .build();
        }
        public iconfiguration configuration { get; }
....

类库中

            var builder = new configurationbuilder()
                .setbasepath(directory.getcurrentdirectory())
                .addjsonfile("appsettings.json")
                .addjsonfile("appsettings.test.json", true, reloadonchange: true);

            var config = builder.build();

            //读取配置
           var a = config["jwtsettings:secret"];

使用.addjsonfile("appsettings.json", optional: true, reloadonchange: true)这种方法可以保证可以修改正在运行的dotnet core 程序，不需要重启程序

使用newtonsoft.json 查询/修改，以及修改 appsettings.json 文件

readobject

        public iactionresult readobject()
        {
            string json = @"{
   'cpu': 'intel',
   'psu': '500w',
   'drives': [
     'dvd read/writer'
     /*(broken)*/,
     '500 gigabyte hard drive',
     '200 gigabyte hard drive'
   ]
}";

            jsontextreader reader = new jsontextreader(new stringreader(json));
            var string1 = "";
            while (reader.read())
            {
                if (reader.value != null)
                {
                    string1 += "reader.value != null: token: " + reader.tokentype + ", value: " + reader.value + " <br/>";
                }
                else
                {
                    string1 += "reader.value == null: token: " + reader.tokentype + " <br/>";
                }
            }

            viewdata["string"] = string1;
            return view();
        }

readjson 读取json 文件

newtonsoft.json

使用newtonsoft.json效果如截图

    public class homecontroller : controller
    {
        private readonly ihostingenvironment _hostingenvironment;
        public homecontroller(ihostingenvironment hostingenvironment)
        {
            _hostingenvironment = hostingenvironment;
        }

        public iactionresult readjson()
        {
            string contentpath = _hostingenvironment.contentrootpath + @"\"; ;   //项目根目录
            var filepath = contentpath + "appsettings.json";
            using (streamreader file = new streamreader(filepath))
            using (jsontextreader reader = new jsontextreader(file))
            {
                jobject o2 = (jobject)jtoken.readfrom(reader);

                string licencekey = (string)o2["appsettings"]["key"];

                viewdata["string"] = licencekey;
                return view();
            }
        }

microsoft.extensions.configuration

使用microsoft.extensions.configuration

        public iactionresult index()
        {
            var builder = new configurationbuilder()
                .setbasepath(directory.getcurrentdirectory())
                .addjsonfile("appsettings.json")
                .addjsonfile("appsettings.test.json", true, reloadonchange: true);

            var config = builder.build();

            //读取配置
            viewdata["secret"] = config["appsettings:key"];
            return view();
        }

修改 appsettings.json后的效果

• newtonsoft.json
  

• microsoft.extensions.configuration
  

修改 appsettings.json

streamwriter直接覆盖

    public class homecontroller : controller
    {
        private readonly ihostingenvironment _hostingenvironment;
        public homecontroller(ihostingenvironment hostingenvironment)
        {
            _hostingenvironment = hostingenvironment;
        }
        public iactionresult writejson()
        {
            string contentpath = _hostingenvironment.contentrootpath + @"\"; ;   //项目根目录
            var filepath = contentpath + "appsettings.json";
            jobject jsonobject;
            using (streamreader file = new streamreader(filepath))
            using (jsontextreader reader = new jsontextreader(file))
            {
                jsonobject = (jobject)jtoken.readfrom(reader);
                jsonobject["appsettings"]["key"] = "asdasdasdasd";
            }

            using (var writer = new streamwriter(filepath))
            using (jsontextwriter jsonwriter = new jsontextwriter(writer))
            {
                jsonobject.writeto(jsonwriter);
            }

            return view();
        }

效果如图

缺点 格式化的json和注释都没了