private static void AddSingleService(IServiceCollection services,
ServiceDescriptor descriptor,
[CanBeNull] DependencyAttribute dependencyAttribute)
{
if (dependencyAttribute?.ReplaceExisting == true)
{
services.Replace(descriptor);
}
else if (dependencyAttribute?.TryAdd == true)
{
services.TryAdd(descriptor);
}
else
{
services.Add(descriptor);
}
}
/// <summary>
/// 将服务实现类型注册到服务集合中
/// </summary>
/// <param name="services">服务集合</param>
/// <param name="implementationType">要注册的服务实现类型</param>
protected virtual void AddToServices(IServiceCollection services, Type implementationType)
{
if (implementationType.IsAbstract || implementationType.IsInterface)
{
return;
}
ServiceLifetime?lifetime = GetLifetimeOrNull(implementationType);
if (lifetime == null)
{
return;
}
DependencyAttribute dependencyAttribute = implementationType.GetAttribute <DependencyAttribute>();
Type[] serviceTypes = GetImplementedInterfaces(implementationType);
//服务数量为0时注册自身
if (serviceTypes.Length == 0)
{
services.TryAdd(new ServiceDescriptor(implementationType, implementationType, lifetime.Value));
return;
}
//服务实现显示要求注册身处时，注册自身并且继续注册接口
if (dependencyAttribute?.AddSelf == true)
{
services.TryAdd(new ServiceDescriptor(implementationType, implementationType, lifetime.Value));
}
//注册服务
for (int i = 0; i < serviceTypes.Length; i++)
{
Type serviceType = serviceTypes[i];
ServiceDescriptor descriptor = new ServiceDescriptor(serviceType, implementationType, lifetime.Value);
if (lifetime.Value == ServiceLifetime.Transient)
{
services.TryAddEnumerable(descriptor);
continue;
}
bool multiple = serviceType.HasAttribute <MultipleDependencyAttribute>();
if (i == 0)
{
if (multiple)
{
services.Add(descriptor);
}
else
{
AddSingleService(services, descriptor, dependencyAttribute);
}
}
else
{
//有多个接口，后边的接口注册使用第一个接口的实例，保证同个实现类的多个接口获得同一实例
Type firstServiceType = serviceTypes[0];
descriptor = new ServiceDescriptor(serviceType, provider => provider.GetService(firstServiceType), lifetime.Value);
if (multiple)
{
services.Add(descriptor);
}
else
{
AddSingleService(services, descriptor, dependencyAttribute);
}
}
}
}