Castle DynamicProxy2:在拦截器中获取目标?
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05-07-2019 - |
题
我正在使用Castle DynamicProxy2来“粘贴”用于从字典中检索字段的接口。例如,给定以下类:
public class DataContainer : IDataContainer
{
private Dictionary<string, object> _Fields = null;
public Dictionary<string, object> Data
{
get { return _Fields ?? (_Fields = new Dictionary<string, object>()); }
}
}
我想使用以下界面作为接口代理来提取“名称”。值字典字典:
public interface IContrivedExample
{
string Name { get; }
}
从拦截器,我想得到“目标” DataContainer,并返回“名称”值:
public void Intercept(IInvocation invocation)
{
object fieldName = omitted; // get field name based on invocation information
DataContainer container = ???; // this is what I'm trying to figure out
invocation.ReturnValue = container.Fields[fieldName];
}
// Somewhere in code
var c = new DataContainer();
c.Fields.Add("Name", "Jordan");
var pg = new ProxyGenerator();
IContrivedExample ice = (IContrivedExample) pg.CreateInterfaceProxyWithTarget(..., c, ...);
Debug.Assert(ice.Name == "Jordan");
关于如何获得基础目标的任何想法
注意:这是一个人为的例子,我用来围绕我的问题建立一些背景。
解决方案
我明白了。您必须将代理转换为IProxyTargetAccessor:
public void Intercept(IInvocation invocation)
{
object fieldName = omitted; // get field name based on invocation information
var accessor = invocation.Proxy as IProxyTargetAccessor;
DataContainer container = (DataContainer) accessor.DynProxyGetTarget();
invocation.ReturnValue = container.Fields[fieldName];
}
其他提示
为什么麻烦?
使用
var container = invocation.InvocationTarget as DataContainer;
BTW,IIUC,你正在尝试实现 Castle DictionaryAdapter 。为什么不使用那里已有的东西? 不隶属于 StackOverflow