/// <summary>
/// 根据类型获取aop实现接口
/// </summary>
/// <param name="providerType">实现接口类型</param>
/// <returns></returns>
IAopOperator GetOperatorProvider(Type providerType)
{
if (providerType == null || providerType.GetInterface(typeof(IAopOperator).FullName) == null)
{
return(null);
}
if (methodOperatorProvider == null || providerType != methodOperatorProvider.GetType())
{
if (providerType == this.target.GetType())
{
methodOperatorProvider = this.target as IAopOperator;
}
else
{
methodOperatorProvider = Activator.CreateInstance(providerType) as IAopOperator;
}
}
return(methodOperatorProvider);
}
/// <summary>
/// 代理调用方法
/// </summary>
/// <param name="msg">方法信息</param>
/// <returns></returns>
public override IMessage Invoke(IMessage msg)
{
IMethodCallMessage call = (IMethodCallMessage)msg;
#region 检索AOP特性标记
AopMethodConfigAttribute methodAopAttr = null;
var attrs = call.MethodBase.GetCustomAttributes(typeof(AopMethodConfigAttribute), false);
if (attrs.Length > 0)
{
methodAopAttr = attrs[0] as AopMethodConfigAttribute;
}
#endregion
#region 方法执行前拦截
if (methodAopAttr != null)
{
var provider = GetOperatorProvider(methodAopAttr.InvokingProvider);
if (provider != null)
{
provider.Invoking(msg);
}
if (methodAopAttr.UseDefaultBeginAop)
{
this.Invoking(msg);
}
}
#endregion
#region 执行方法
IMethodReturnMessage returnMsg = null;
//如果触发的是构造函数，此时target的构建还未开始
IConstructionCallMessage ctor = call as IConstructionCallMessage;
if (ctor != null)
{
//获取最底层的默认真实代理
RealProxy default_proxy = RemotingServices.GetRealProxy(this.target);
default_proxy.InitializeServerObject(ctor);
MarshalByRefObject tp = (MarshalByRefObject)this.GetTransparentProxy(); //自定义的透明代理 this
return(EnterpriseServicesHelper.CreateConstructionReturnMessage(ctor, tp));
}
else
{
returnMsg = RemotingServices.ExecuteMessage(this.target, call); //将消息转化为堆栈，并执行目标方法，方法完成后，再将堆栈转化为消息
}
#endregion
#region 异常处理
if (returnMsg.Exception != null)
{
IAopOperator provider = null;
if (methodAopAttr != null)
{
provider = GetOperatorProvider(methodAopAttr.OnExceptionProvider);
}
if (provider != null)
{
provider.OnException(msg, returnMsg.Exception);
}
else if ((target as IException) != null)
{
((IException)target).OnException(msg, returnMsg.Exception);
}
else
{
this.OnException(msg, returnMsg.Exception);
}
object value = null;
var methodInfo = (System.Reflection.MethodInfo)returnMsg.MethodBase;
if (methodInfo.ReturnType != typeof(void) && methodAopAttr != null && methodAopAttr.ReturnExceptionDefaultValue)
{
value = Activator.CreateInstance(methodInfo.ReturnType, methodAopAttr.ExceptionDefaultValue);
}
returnMsg = new ReturnMessage(value, returnMsg.OutArgs, returnMsg.OutArgCount, returnMsg.LogicalCallContext, call);
}
#endregion
#region 方法执行后拦截
else if (methodAopAttr != null)
{
var provider = GetOperatorProvider(methodAopAttr.InvokedProvider);
if (provider != null)
{
provider.Invoked(msg, returnMsg);
}
if (methodAopAttr.UseDefaultEndAop)
{
this.Invoked(msg, returnMsg);
}
}
#endregion
return(returnMsg);
}
