配置文件appsettings.json
1 本篇概述
本篇描述appsettings.json的使用，包括：
- 配置的基本读取
- 读取配置信息到自定义的对象
- 自定义配置文件
1 配置的基本读取
要读取的配置文件内容如下：
{ "ConnString": "MySQL Connect String", "Logging": { "IncludeScopes": false, "Debug": { "LogLevel": { "Default": "Warning" } }, "Console": { "LogLevel": { "Default": "Warning" } } }, "SystemConfig": { "UploadFile": "d:\\files", "AnnexUrl": "http://192.168.0.177:81/", "Admin": { "Name": "admin", "Age": "31", "Allow": "True" }, "DefaultPassword": "123456" } }
读取配置文件的方法如下：
public class Startup
{
public Startup(IConfiguration configuration,IHostingEnvironment env)
{
Configuration = configuration;
_env = env;
}
public IConfiguration Configuration { get; }
public IHostingEnvironment _env { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
var ConnString = Configuration["ConnString"];
var UploadFile = Configuration.GetSection("SystemConfig")["UploadFile"];
var AdminName = Configuration.GetSection("SystemConfig").GetSection("Admin")["Name"];
}
}
还有一种读法:
ConnString = Configuration["ConnString"]; UploadFile = Configuration["SystemConfig:UploadFile"]; AdminName = Configuration["SystemConfig:Admin:Name"];
这里Startup类在构造时已经帮我们注入了Configuration，如果要在自己的Controller内使用，需要自己注入。
public class ValuesController: Controller
{
private IConfiguration _configuration;
public ValuesController(IConfiguration configuration)
{
_configuration = configuration;
}
[HttpGet]
public IEnumerable < string > Get()
{
var ConnString = _configuration["ConnString"];
return new string[]
{
"value1", "value2"
};
}
}
2 读取配置信息到自定义的对象
新建一个类，用来存储配置信息，类的结构应和配置文件一致。
public class SystemConfig
{
public String UploadFile
{
get;
set;
}
public String AnnexUrl
{
get;
set;
}
public User Admin
{
get;
set;
}
public String DefaultPassword
{
get;
set;
}
}
public class User
{
public String Name
{
get;
set;
}
public int Age
{
get;
set;
}
public bool Allow
{
get;
set;
}
}
在startup类的ConfigureServices方法内，提供如下代码：
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration
{
get;
}
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddOptions();
services.Configure < SystemConfig > (Configuration.GetSection("SystemConfig"));
}
}
}
然后在Controller中进行注入并使用。
public class ValuesController: Controller
{
private IOptions < SystemConfig > _setting;
public ValuesController(IOptions < SystemConfig > setting)
{
_setting = setting;
}
[HttpGet("setting")]
public IEnumerable < string > GetSetting()
{
var UploadFile = _setting.Value.UploadFile;
var AdminName = _setting.Value.Admin.Name;
var AdminAge = _setting.Value.Admin.Age;
var AdminAllow = _setting.Value.Admin.Allow;
return new string[]
{
"value1", "value2"
};
}
}
可以看到，这样在业务方法内通过 _setting 来都取配置信息就非常方便了。
3 自定义配置文件
以上操作的是系统默认的配置文件appsettings.json。如果我们需要增加自己的配置文件该如何处理？
新建一个配置文件：mysetting.json
{ "ConnString": "MySQL Connect String", "SystemConfig": { "UploadFile": "d:\\myfiles", "AnnexUrl": "http://192.168.0.177:81/my", "Admin": { "Name": "myadmin", "Age": "131", "Allow": "False" }, "DefaultPassword": "654321" } }
在Startup类的ConfigureServices方法输入以下代码:
public class Startup
{
public Startup(IConfiguration configuration, IHostingEnvironment env)
{
Configuration = configuration;
_env = env;
}
public IConfiguration Configuration
{
get;
}
public IHostingEnvironment _env
{
get;
}
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
var rootpath = _env.ContentRootPath;
var builder = new ConfigurationBuilder().SetBasePath(_env.ContentRootPath).AddJsonFile("mysetting.json", optional: true, reloadOnChange: true).AddEnvironmentVariables();
var MyConfiguration = builder.Build();
services.AddOptions();
services.Configure < SystemConfig > (MyConfiguration.GetSection("SystemConfig"));
}
}
用自己创建的Configuration进行服务的注册，创建过程中需要用到IHostingEnvironment，这个对象在Startup类构建时进行注入。
剩下的用法和默认配置用法就一样了。
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本文为智客工坊「seabluescn」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
