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我想了解如何使用Castle Windsor IoC，并且在理解如何配置某些对象时遇到一些困难我需要动态解析。基本上，我有几个IDataSource的实现，我需要根据如何配置特定的“数据源”来选择要使用的实现。所以我可能会将相当多的数据源配置为使用3种实现中的一种。我的期望是，依赖代码将依赖于一个工厂方法，当它提供了“数据源ID”以及数据源实现需要的依赖项（IPrincipal）时，将为它们提供正确的IDataSource。如何配置Castle Windsor根据提供给Resolve（）的参数（除名称以外）动态选择提供程序
我正在努力如何正确书写温莎的注册代表。下面大概是我得到的。我试图使用DynamicParameters方法（可能不是正确的使用方法）执行逻辑，该逻辑计算出要使用哪种实现，然后调用Resolve来提取该特定版本。但我不知道如何返回已解决的对象，因为DynamicParameters预计为ComponentReleasingDelegate，我假设它应该是类似return k => { k.ReleaseComponent(dataSource); }的东西。但是，那么我如何让我获得的数据源返回到容器，以便它返回给调用者？
struct DataSourceInfo {
string Id;
string ProviderType;
}
interface ICatalog : IDictionary<string /* Id */, DataSourceInfo> {
/* ... */
}
class Catalog : ICatalog {
/* implement dictionary which looks up DataSourceInfo from their string id */
}
interface IDataSource { /* ... */ }
class Source1 : IDataSource {
Source1(string id, IPrincipal principal) { /* ... */ }
}
class Source2 : IDataSource {
Source2(string id, IPrincipal principal) { /* ... */ }
}
/* ... */
/* ... inside Windsor configuration section */
container.Register(Component.For<ICatalog>().LifeStyle.Singleton.ImplementedBy<Catalog>());
// Default service provider is a factory method which uses the string (data source id)
// and looks up the DataSourceInfo from the ICatalog. It then uses info.ProviderType
// to request IoC to resolve that specific implementation and passes in "id" and "principal"
// to be used to resolve the dependencies of the implementation
container.Register(Component.For<IDataSource>().LifeStyle.Transient
.DynamicParameters((kernel, context, args) => {
if (args == null || !args.Contains("id") || !(args["id"] is string)) throw ApplicationException("bad args");
var id = (string)args["id"];
var catalog = kernel.Resolve<ICatalog>();
DataSourceInfo info;
try { info = catalog[id]; } finally { kernel.ReleaseComponent(catalog); }
// Now resolve the actual IDataSource
var dataSource = kernel.Resolve<IDataSource>(info.ProviderType, args);
// How do I return dataSource???
});
// Now register the actual implementations
container.Register(Component.For<IDataSource>().LifeStyle.Transient.ImplementedBy<Source1>().Named("Source1"));
container.Register(Component.For<IDataSource>().LifeStyle.Transient.ImplementedBy<Source2>().Named("Source2"));
/* ... */
/* some application startup code which configures some data sources */
class AppConfigurer {
AppConfigurer(ICatalog catalog) {
catalog["sourceA"] = new DataSourceInfo() { Id = "sourceA", ProviderType = "Source1" }; // data sourceA is provided by Source1 class
catalog["sourceB"] = new DataSourceInfo() { Id = "sourceB", ProviderType = "Source2" }; // data sourceB is provided by Source2 class
catalog["sourceC"] = new DataSourceInfo() { Id = "sourceC", ProviderType = "Source2" }; // data sourceC is provided by Source2 class
catalog["sourceD"] = new DataSourceInfo() { Id = "sourceD", ProviderType = "Source2" }; // data sourceD is provided by Source2 class
catalog["sourceE"] = new DataSourceInfo() { Id = "sourceE", ProviderType = "Source1" }; // data sourceE is provided by Source1 class
}
}
// Here is where I actually want to use IDataSources, and I do not want to know all the business about IDataSourceInfo. I just know a dataSourceId and an IPrincipal and want to get an IDataSource to work with.
class Dependant {
Dependant (Func<string, IPrincipal, IDataSource> factory) {
var sourceA = factory("sourceA", somePrincipal); // sourceA.GetType() == typeof(Source1)
var sourceB = factory("sourceB", somePrincipal); // sourceB.GetType() == typeof(Source2)
var sourceC = factory("sourceC", somePrincipal); // sourceC.GetType() == typeof(Source2)
}
}
编辑：切换从DynamicParameters到UsingFactoryMethod我可以做我想做的。但我一直认为这是错误的，因为现在如果我做container.ResolveAll()我真的很喜欢它跳过工厂方法，但我不知道如何让它做到这一点。