public T Resolve <T>()
{
RegisterInfo info = davidContainerDic[typeof(T).FullName];
Type type = davidContainerDic[typeof(T).FullName].TargetType;
T result = default(T);
//对生命周期进行处理
switch (info.LiftTime)
{
case LifeTimeType.Transient:
result = (T)this.CreateObject(type);
break;
case LifeTimeType.Singleton:
if (this.TypeObjectDic.ContainsKey(type))
{
result = (T)this.TypeObjectDic[type];
}
else
{
result = (T)this.CreateObject(type);
this.TypeObjectDic.Add(type, result);
}
break;
case LifeTimeType.PerThread:
//线程槽,netcore已经不支持CallContext,自己封装一个
{
string key = type.FullName;
object oValue = CallContext.GetData(key);
if (oValue == null)
{
result = (T)this.CreateObject(type);
CallContext.SetData(key, result);
}
else
{
result = (T)oValue;
}
}
break;
default:
throw new Exception("Wrong");
}
return(result);
}
/// <summary>
/// 递归实现构造函数的参数查找
/// </summary>
/// <param name="type"></param>
/// <returns></returns>
private object CreateObject(Type type)
{
//找有参数构造函数,先进行特性判断
ConstructorInfo[] ctorArray = type.GetConstructors();
ConstructorInfo ctor = null;
if (ctorArray.Count(c => c.IsDefined(typeof(DavidInjectionConstructorAttribute), true)) > 0)
{
ctor = ctorArray.FirstOrDefault(c => c.IsDefined(typeof
(DavidInjectionConstructorAttribute), true));
}
else
{
//如果没有特性的话，就找参数最多的那个构造函数
ctor = ctorArray.OrderByDescending(c => c.GetParameters().Length).FirstOrDefault();
}
//获取到构造函数参数
List <object> paraList = new List <object>();
foreach (var parameter in ctor.GetParameters())
{
//需要构造注入的对象，依赖对象
//这个是抽象类型，不能直接构造实例，所以需要从字典中获取真实的实例类型进行构造
Type paraType = parameter.ParameterType;
RegisterInfo info = this.davidContainerDic[paraType.FullName];
Type targetType = info.TargetType;
//继续检查targetType的构造函数，需要通过递归实现
//object para = this.CreateObject(targetType);
object para = null;
#region
switch (info.LiftTime)
{
case LifeTimeType.Transient:
para = this.CreateObject(targetType);
break;
case LifeTimeType.Singleton:
//线程不安全，需要通过双if+lock
if (this.TypeObjectDic.ContainsKey(targetType))
{
para = this.TypeObjectDic[targetType];
}
else
{
para = this.CreateObject(targetType);
this.TypeObjectDic.Add(targetType, para);
}
break;
case LifeTimeType.PerThread:
//线程槽,netcore已经不支持CallContext,自己封装一个
{
string key = type.FullName;
object oValue = CallContext.GetData(key);
if (oValue == null)
{
para = this.CreateObject(targetType);
CallContext.SetData(key, para);
}
else
{
para = oValue;
}
}
break;
default:
throw new Exception("Wrong");
}
#endregion
paraList.Add(para);
}
return(Activator.CreateInstance(type, paraList.ToArray()));
}
