通过ConfigurationManager使用.NET配置文件时，可以通过添加配置文件进行单元测试，虽然可以通过测试但达不到解耦的目的。使用IConfigurationManager和ConfigurationManagerWrapper对ConfigurationManager进行适配是更好的方式，ConfigurationManagerWrapper提供.NET配置文件方式的实现，如果需要支持其他配置，创建IConfigurationManager接口的不同的实现类即可。
1.定义IConfigurationManager接口原本依赖ConfigurationManager的代码现在依赖IConfigurationManager。可以在单元测试时方便的Mock。
publicinterfaceIConfigurationManager
{
NameValueCollection AppSettings {get; }
ConnectionStringSettingsCollection ConnectionStrings {get; }objectGetSection(stringsectionName);
}
2.创建适配类ConfigurationManagerWrapper非单元测试环境使用ConfigurationManagerWrapper作为IConfigurationManager的默认实现。
publicclassConfigurationManagerWrapper : IConfigurationManager
{publicNameValueCollection AppSettings
{get{returnConfigurationManager.AppSettings;
}
}publicConnectionStringSettingsCollection ConnectionStrings
{get{returnConfigurationManager.ConnectionStrings;
}
}publicobjectGetSection(stringsectionName)
{returnConfigurationManager.GetSection(sectionName);
}
}
3.自定义泛型配置接口在我们的代码需要使用配置时，可以考虑创建通用的泛型接口也可以使用专用的强类型的接口。这里演示使用通用的接口。
publicinterfaceIConfiguration
{
T Get<T>(stringkey, T @default);
}
4.实现泛型接口配置接口的.NET配置文件版本AppConfigAdapter直接不使用ConfigurationManager而是依赖IConfigurationManager接口。
publicclassAppConfigAdapter : IConfiguration
{PRivateIConfigurationManager _configurationManager;publicAppConfigAdapter(IConfigurationManager configurationManager)
{this._configurationManager =configurationManager;
}publicT Get<T>(stringnodeName, T @default)
{varvalue =this._configurationManager.AppSettings[nodeName];returnvalue ==null? @default : (T)Convert.ChangeType(value,typeof(T));
}
}
5.对泛型配置接口的实现进行单元测试使用最流行的单元测试框架和Mock类库：xUnit+Moq进行单元测试。
publicclassAppConfigAdapterTest
{
[Fact]publicvoidGetStringTest()
{varkey ="key";varvalue ="value";varconfiguration =newAppConfigAdapter(this.GetConfigurationManager(o =>o.Add(key, value.ToString())));
Assert.Equal(configuration.Get(key,string.Empty), value);
}
[Fact]publicvoidGetIntTest()
{varkey ="key";varvalue =1;varconfiguration =newAppConfigAdapter(this.GetConfigurationManager(o =>o.Add(key, value.ToString())));
Assert.Equal(configuration.Get(key,int.MinValue), value);
}
[Fact]publicvoidGetBoolTest()
{varkey ="key";varvalue =true;varconfiguration =newAppConfigAdapter(this.GetConfigurationManager(o =>o.Add(key, value.ToString())));
Assert.Equal(configuration.Get(key,false), value);
}
[Fact]publicvoidGetDateTimeTest()
{varkey ="key";varvalue =DateTime.Parse(DateTime.Now.ToString());varconfiguration =newAppConfigAdapter(this.GetConfigurationManager(o =>o.Add(key, value.ToString())));
Assert.Equal(configuration.Get(key, DateTime.MinValue), value);
}
[Fact]publicvoidGetDecimalTest()
{varkey ="key";varvalue =1.1m;varconfiguration =newAppConfigAdapter(this.GetConfigurationManager(o =>o.Add(key, value.ToString())));
Assert.Equal(configuration.Get(key,decimal.MinValue), value);
}privateIConfigurationManager GetConfigurationManager(Action<NameValueCollection>set)
{varappSettings =newNameValueCollection();set(appSettings);varconfigurationManager =newMock<IConfigurationManager>();
configurationManager.Setup(o=>o.AppSettings).Returns(appSettings);returnconfigurationManager.Object;
}
}
运行结果：
[flash=500,400]http://s1.knowsky.com/20160211/nynhspajl0g29.png[/flash]
6.总结使依赖ConfigurationManager静态类的代码转换为依赖IConfigurationManager接口，运行时注入ConfigurationManagerWrapper实现类。单元测试时使用Mock模拟IConfigurationManager对象。