我想在Autofac中为每个匹配的生命周期范围注册创建一个实例,但偶尔需要从全局容器(没有匹配的生命周期范围)请求实例.在没有匹配的生命周期范围的情况下,我想提供一个顶级实例而不是抛出异常.
这可能吗？
解决方法
我认为你最好通过引入新的生命周期选项来扩展Autofac.我使用了Autofac源并对其进行了一些修改：
public static class RegistrationBuilderExtensions
{
public static IRegistrationBuilder<TLimit,TActivatorData,TRegistrationStyle> InstancePerMatchingOrRootLifetimeScope<TLimit,TRegistrationStyle>(this IRegistrationBuilder<TLimit,TRegistrationStyle> builder,params object[] lifetimeScopeTag)
{
if (lifetimeScopeTag == null) throw new ArgumentNullException("lifetimeScopeTag");
builder.RegistrationData.Sharing = InstanceSharing.Shared;
builder.RegistrationData.Lifetime = new MatchingScopeOrRootLifetime(lifetimeScopeTag);
return builder;
}
}
public class MatchingScopeOrRootLifetime: IComponentLifetime
{
readonly object[] _tagsToMatch;
public MatchingScopeOrRootLifetime(params object[] lifetimeScopeTagsToMatch)
{
if (lifetimeScopeTagsToMatch == null) throw new ArgumentNullException("lifetimeScopeTagsToMatch");
_tagsToMatch = lifetimeScopeTagsToMatch;
}
public ISharingLifetimeScope FindScope(ISharingLifetimeScope mostNestedVisibleScope)
{
if (mostNestedVisibleScope == null) throw new ArgumentNullException("mostNestedVisibleScope");
var next = mostNestedVisibleScope;
while (next != null)
{
if (_tagsToMatch.Contains(next.Tag))
return next;
next = next.ParentLifetimeScope;
}
return mostNestedVisibleScope.RootLifetimeScope;
}
}
builder.RegisterType<A>.InstancePerMatchingOrRootLifetimeScope("TAG");
我自己没试过,但它应该有用.
