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我有一個相對動態的事件過程，我需要能夠解釋傳遞給動態處理程序的參數，但我遇到了麻煩。傳遞和解釋參數 - 動態處理程序
請注意，下面的代碼是100％的功能。它只是需要調整以滿足要求。
下面是一個簡單的類，它定義了一個Action和Event。 OnLeftClickEvent（）方法接收由於事件約束而產生的args對象[]，必須封裝在EventArgs中。
public class SomeSubscriber : SubscriberBase
{
private Logger<SomeSubscriber> debug = new Logger<SomeSubscriber>();
public Action LeftClickAction;
public event EventHandler LeftClickEvent;
public SomeSubscriber()
{
LeftClickAction += OnLeftClickEvent;
}
public void OnLeftClickEvent(params object[] args)
{
AppArgs eventArgs = new AppArgs(this, args);
if(LeftClickEvent != null) LeftClickEvent(this, eventArgs);
}
}
在接收端是實現動態處理程序和觸發事件的類：
public class EventControllBase : _MonoControllerBase
{
private Logger<EventControllBase> debug = new Logger<EventControllBase>();
SomeSubscriber subscriber;
private void Start()
{
subscriber = new SomeSubscriber();
subscriber.AddHandler("LeftClickEvent", e =>
{
debug.LogWarning(string.Format("Received {0} from {1} ", e[1], e[0]));
return true;
});
}
private void Update()
{
if(Input.GetMouseButtonDown(0))
{ // Trigger events.
subscriber.InvokeDelegate("LeftClickAction", (object) new object[]{ this, Input.mousePosition });
}
}
}
在我定義在更新（動態處理程序，並開始（）方法）其被觸發並傳遞所需的數據。
e [1]顯然是EventArgs類型（AppArgs：EventArgs是特定的），但我不確定如何訪問成員以獲取實例中的數據。我嘗試過鑄造，但它是一個不行。
這裏是AppArgs的身體，如果有幫助：
public class AppArgs : EventArgs
{
public object sender {get; private set;}
private object[] _args;
public AppArgs(object sender, object[] args)
{
this.sender = sender;
this._args = args;
}
public object[] args()
{
return this._args;
}
}
動態處理器
public static class DynamicHandler
{
/// <summary>
/// Invokes a static delegate using supplied parameters.
/// </summary>
/// <param name="targetType">The type where the delegate belongs to.</param>
/// <param name="delegateName">The field name of the delegate.</param>
/// <param name="parameters">The parameters used to invoke the delegate.</param>
/// <returns>The return value of the invocation.</returns>
public static object InvokeDelegate(this Type targetType, string delegateName, params object[] parameters)
{
return ((Delegate)targetType.GetField(delegateName).GetValue(null)).DynamicInvoke(parameters);
}
/// <summary>
/// Invokes an instance delegate using supplied parameters.
/// </summary>
/// <param name="target">The object where the delegate belongs to.</param>
/// <param name="delegateName">The field name of the delegate.</param>
/// <param name="parameters">The parameters used to invoke the delegate.</param>
/// <returns>The return value of the invocation.</returns>
public static object InvokeDelegate(this object target, string delegateName, params object[] parameters)
{
return ((Delegate)target.GetType().GetField(delegateName).GetValue(target)).DynamicInvoke(parameters);
}
/// <summary>
/// Adds a dynamic handler for a static delegate.
/// </summary>
/// <param name="targetType">The type where the delegate belongs to.</param>
/// <param name="fieldName">The field name of the delegate.</param>
/// <param name="func">The function which will be invoked whenever the delegate is invoked.</param>
/// <returns>The return value of the invocation.</returns>
public static Type AddHandler(this Type targetType, string fieldName,
Func<object[], object> func)
{
return InternalAddHandler(targetType, fieldName, func, null, false);
}
/// <summary>
/// Adds a dynamic handler for an instance delegate.
/// </summary>
/// <param name="target">The object where the delegate belongs to.</param>
/// <param name="fieldName">The field name of the delegate.</param>
/// <param name="func">The function which will be invoked whenever the delegate is invoked.</param>
/// <returns>The return value of the invocation.</returns>
public static Type AddHandler(this object target, string fieldName,
Func<object[], object> func)
{
return InternalAddHandler(target.GetType(), fieldName, func, target, false);
}
/// <summary>
/// Assigns a dynamic handler for a static delegate or event.
/// </summary>
/// <param name="targetType">The type where the delegate or event belongs to.</param>
/// <param name="fieldName">The field name of the delegate or event.</param>
/// <param name="func">The function which will be invoked whenever the delegate or event is fired.</param>
/// <returns>The return value of the invocation.</returns>
public static Type AssignHandler(this Type targetType, string fieldName,
Func<object[], object> func)
{
return InternalAddHandler(targetType, fieldName, func, null, true);
}
/// <summary>
/// Assigns a dynamic handler for a static delegate or event.
/// </summary>
/// <param name="target">The object where the delegate or event belongs to.</param>
/// <param name="fieldName">The field name of the delegate or event.</param>
/// <param name="func">The function which will be invoked whenever the delegate or event is fired.</param>
/// <returns>The return value of the invocation.</returns>
public static Type AssignHandler(this object target, string fieldName, Func<object[], object> func)
{
return InternalAddHandler(target.GetType(), fieldName, func, target, true);
}
private static Type InternalAddHandler(Type targetType, string fieldName,
Func<object[], object> func, object target, bool assignHandler)
{
Type delegateType;
var bindingFlags = BindingFlags.Public | BindingFlags.NonPublic |
(target == null ? BindingFlags.Static : BindingFlags.Instance);
var eventInfo = targetType.GetEvent(fieldName, bindingFlags);
if (eventInfo != null && assignHandler)
throw new ArgumentException("Event can be assigned. Use AddHandler() overloads instead.");
if (eventInfo != null)
{
delegateType = eventInfo.EventHandlerType;
var dynamicHandler = BuildDynamicHandler(delegateType, func);
eventInfo.GetAddMethod(true).Invoke(target, new Object[] { dynamicHandler });
}
else
{
var fieldInfo = targetType.GetField(fieldName);
//,target == null ? BindingFlags.Static : BindingFlags.Instance);
delegateType = fieldInfo.FieldType;
var dynamicHandler = BuildDynamicHandler(delegateType, func);
var field = assignHandler ? null : target == null
? (Delegate)fieldInfo.GetValue(null)
: (Delegate)fieldInfo.GetValue(target);
field = field == null
? dynamicHandler
: Delegate.Combine(field, dynamicHandler);
if (target != null)
target.GetType().GetField(fieldName).SetValue(target, field);
else
targetType.GetField(fieldName).SetValue(null, field);
//(target ?? targetType).SetFieldValue(fieldName, field);
}
return delegateType;
}
/// <summary>
/// Dynamically generates code for a method whose can be used to handle a delegate of type
/// <paramref name="delegateType"/>. The generated method will forward the call to the
/// supplied <paramref name="func"/>.
/// </summary>
/// <param name="delegateType">The delegate type whose dynamic handler is to be built.</param>
/// <param name="func">The function which will be forwarded the call whenever the generated
/// handler is invoked.</param>
/// <returns></returns>
public static Delegate BuildDynamicHandler(this Type delegateType, Func<object[], object> func)
{
var invokeMethod = delegateType.GetMethod("Invoke");
var parameters = invokeMethod.GetParameters().Select(parm =>
Expression.Parameter(parm.ParameterType, parm.Name)).ToArray();
var instance = func.Target == null ? null : Expression.Constant(func.Target);
var convertedParameters = parameters.Select(parm => Expression.Convert(parm, typeof(object))).Cast<Expression>().ToArray();
var call = Expression.Call(instance, func.Method, Expression.NewArrayInit(typeof(object), convertedParameters));
var body = invokeMethod.ReturnType == typeof(void)
? (Expression)call
: Expression.Convert(call, invokeMethod.ReturnType);
var expr = Expression.Lambda(delegateType, body, parameters);
return expr.Compile();
}
}
您的'Subscriber'類沒有'AddHandler'方法，所以此時此時不起作用。你可以使用'subscriber.LeftClickEvent + = ...' - 但說實話，根本不清楚爲什麼你有一個'Subscriber'類。它是什麼增加了.NET已經提供的代表和事件？ –
@Jon它可能從'SubscriberBase'繼承。 @Xerosigma你可以包含'AddHandler'的實現嗎？ –
@MikePrecup：啊，錯過了，是的。儘管如此，我仍然不清楚它的目的是什麼......看起來它正在重新發明輪子。 –