嵌套对象C＃中的“对象引用未设置为对象的实例”

Question

我是C＃和WPF的新手。我有一个课程和其他嵌套课程。

class jsonConfig
{
    public obj_info info { get; set; }
    public string server { get; set; }
    public string status { get; set; }
    public string workstation { get; set; }
    public Boolean transmite_data { get; set; }

    public class obj_info
    {
        public string System { get; set; }
        public string application { get; set; }
        public string version { get; set; }
        public DateTime build_date { get; set; }
    }
}

，当我尝试为“ jConfig.info”下的任何对象分配值时。我收到一个错误： “对象引用未设置为对象的实例”

            jsonConfig jConfig = new jsonConfig();

            jConfig.info.System =  "ROSS";
            jConfig.info.application = "WatchDog";
            jConfig.info.version = "2.0.0";
            jConfig.info.build_date = new DateTime(2019,01,08);

            jConfig.server = "https://ross.client.com";
            jConfig.status = "Connected";
            jConfig.transmite_data = false;