C# Ioc容器Unity，簡單實用

開頭先吐槽一下博客園超級不好用，添加圖片后就寫不動字了，難道是bug

好進入正題，先來說下依賴注入，簡單來說就是定義好接口，上層代碼調用接口，具體實現通過配置文件方式去指定具體實現類。

首先我們需要通過nuget來安裝unity

安裝好后就可以寫一個方法類去實現依賴注入

public class UnityIocHelper : IServiceProvider
    {
        private readonly IUnityContainer _container;
        private static readonly UnityIocHelper dbinstance = new UnityIocHelper("DBcontainer");
        private UnityIocHelper(string containerName)
        {
            UnityConfigurationSection section = (UnityConfigurationSection)ConfigurationManager.GetSection("unity");
            _container = new UnityContainer();
            section.Configure(_container, containerName);
        }

        public static UnityIocHelper DBInstance
        {
            get { return dbinstance; }
        }
        public object GetService(Type serviceType)
        {
            return _container.Resolve(serviceType);
        }
        public T GetService<T>()
        {
            return _container.Resolve<T>();
        }
        public T GetService<T>(params ParameterOverride[] obj)
        {
            return _container.Resolve<T>(obj);
        }
        public T GetService<T>(string name, params ParameterOverride[] obj)
        {
            return _container.Resolve<T>(name, obj);
        }
    }

具體調用方法

public static IDatabase Base(string connString)
        {
            return UnityIocHelper.DBInstance.GetService<IDatabase>(“MySql”, new ParameterOverride(
              "connString", connString));
        }

配置信息

<unity>
  <typeAliases>
    <typeAlias alias="IDatabase" type="LRMC.Data.IDatabase,LRMC.Data" />
    <typeAlias alias="SqlServer" type="LRMC.Data.SqlDapper.Database,LRMC.Data.SqlDapper" />
    <typeAlias alias="MySql"     type="LRMC.Data.MySqlDapper.Database,LRMC.Data.MySqlDapper" />
  </typeAliases>
  <containers>
    <container name="DBcontainer">
      <!-- 默認數據庫軟件類型：SqlServer,MySql,Oracle,Access,SQLite-->
      <type type="IDatabase" mapTo="SqlServer" name="SqlServer"></type >
      <type type="IDatabase" mapTo="MySql" name="MySql"></type >
    </container>
  </containers>
</unity>

typeAlias 指定一個類的別名，

<type type="IDatabase" mapTo="MySql" name="MySql"></type >就是

IDatabase這個接口通過

MySql（

LRMC.Data.MySqlDapper.Database

）這個類去實現。