.net core 学习 读取配置文件

在空项目中是没有配置文件的，首先要新建一个，配置文件内容如下，下面来读取各个内容

{
  "connectionstrings": {
    "defaultconnection": "server=(localdb)\\mssqllocaldb;database=_change_me;trusted_connection=true;multipleactiveresultsets=true",
  },
  "name": "张三",
  "person": {
    "name": "张三",
    "age": 18
  },
  "persons": [
    {
      "name": "张三",
      "age": 18
    },
    {
      "name": "李四",
      "age": 18
    }
  ]
}

有时会出现中文读取乱码，用计事本打开，然后另存为 utf-8 就可以了

configurationbuilder configurationbuilder =new configurationbuilder();
//配置文件路径
configurationbuilder.setbasepath(directory.getcurrentdirectory()).addjsonfile("appsettings.json");
var configuration = configurationbuilder.build();
            
//读取连接字符串
var value1= configuration.getconnectionstring("defaultconnection");

//读取自定义内容
var value2 = configuration.getvalue<string>("name");
var value3 = configuration.getvalue<string>("person:name");
var value4 = configuration.getvalue<int>("person:age");
var value5 = configuration.getvalue<string>("persons:0:name");
var value6 = configuration.getvalue<int>("persons:0:age");

索引不是中括号感觉有点不适应

上面是读取基础值，其实还可以将 person 和 persons 读取为对象，不过写法要改下，首先再 startup 类中添加一个构造函数和字段

public startup(iconfiguration _configuration)
{
   configuration = _configuration;
}

public iconfiguration configuration;

然后在 configureservices 方法添加如下

services.configure<person>(configuration.getsection("person"));
services.configure<list<person>>(configuration.getsection("persons"));

之后是控制器中

private person person;
private list<person> persons;
public configurationcontroller(ioptions<person> _person, ioptions<list<person>> _persons)
{
    person = _person.value;
    persons = _persons.value;
}

以上就是 asp.net core 读取配置文件的方法