/// <summary>
/// 构建事件
/// </summary>
/// <param name="member"></param>
/// <param name="members"></param>
/// <param name="exists"></param>
/// <param name="typeBuilder">类型构建</param>
/// <param name="sourceTypeOrInterfaceType">假如是承继父类的，则callBase就能生效</param>
/// <param name="buildInterface">构建接口</param>
protected virtual void BuildEvent(MemberInfo member, MemberInfo[] members, List <MemberInfo> exists, TypeBuilder typeBuilder, Type sourceTypeOrInterfaceType, bool @buildInterface)
{
var @event = member as EventInfo;
exists.Add(@event);
var addName = string.Concat("add_", @event.Name);
var removeName = string.Concat("remove_", @event.Name);
MethodInfo addMethod = null, removeMethod = null;
foreach (var m in members)
{
if (m.MemberType == MemberTypes.Method)
{
if (addName == m.Name)
{
addMethod = (MethodInfo)m;
exists.Add(m);
if (removeMethod != null)
{
break;
}
}
else if (removeName == m.Name)
{
removeMethod = (MethodInfo)m;
exists.Add(m);
if (addMethod != null)
{
break;
}
}
}
}
FieldBuilder fieldBuilder = null;
EventBuilder eventBuilder = null;
if (!@buildInterface && (addMethod == null || addMethod.IsFinal) && (removeMethod == null || removeMethod.IsFinal))
{
return;
}
eventBuilder = typeBuilder.DefineEvent(@event.Name, @event.Attributes, @event.EventHandlerType);
if (addMethod != null)
{
fieldBuilder = typeBuilder.DefineField(@event.Name, @event.EventHandlerType, FieldAttributes.Private);
/*泛型方法和基本方法有什么不同*/
var parameters = addMethod.GetParameters();
var parameterTypes = new List <Type>(parameters.Length);
var voidReturn = addMethod.ReturnType == typeof(void);
foreach (var parameter in parameters)
{
parameterTypes.Add(parameter.ParameterType);
}
var attributes = MethodAttributes.Public | MethodAttributes.Virtual | MethodAttributes.HideBySig | MethodAttributes.SpecialName;
if (!buildInterface)
{
attributes = MethodAttributes.Public | MethodAttributes.ReuseSlot | MethodAttributes.Virtual | MethodAttributes.HideBySig;
}
var methodBuilder = typeBuilder.DefineMethod(addMethod.Name,
attributes,
addMethod.CallingConvention,
addMethod.ReturnType, parameterTypes.ToArray());
/*fix argument length*/
parameterTypes.Insert(0, sourceTypeOrInterfaceType);
var il = new MockEmitBuilder(methodBuilder.GetILGenerator(), addMethod.CallingConvention, addMethod.ReturnType, parameterTypes.ToArray());
var locals = new[]
{
il.DeclareLocal(@event.EventHandlerType),
il.DeclareLocal(@event.EventHandlerType),
il.DeclareLocal(@event.EventHandlerType),
};
var label = il.DefineLabel();
il.LoadArgument(0);
il.LoadField(fieldBuilder);
il.StoreLocal(locals[0]);
il.MarkLabel(label);
il.LoadLocal(locals[0]);
il.StoreLocal(locals[1]);
il.LoadLocal(locals[1]);
il.LoadArgument(1);
MethodInfo delegateMethod = null;
foreach (var method in typeof(System.Delegate).GetMethods(BindingFlags.Public | BindingFlags.Static))
{
if (method.Name == "Combine" && method.GetParameters().Length == 2)
{
delegateMethod = method;
break;
}
}
il.Call(delegateMethod);
il.CastClass(@event.EventHandlerType);
il.StoreLocal(locals[2]);
il.LoadArgument(0);
il.LoadFieldAddress(fieldBuilder);
il.LoadLocal(locals[2]);
il.LoadLocal(locals[1]);
foreach (var method in typeof(System.Threading.Interlocked).GetMethods(BindingFlags.Public | BindingFlags.Static))
{
if (method.Name == "CompareExchange" && method.IsGenericMethod && method.GetParameters().Length == 3)
{
delegateMethod = method;
break;
}
}
il.Call(delegateMethod.MakeGenericMethod(new[] { @event.EventHandlerType }));
il.StoreLocal(locals[0]);
il.LoadLocal(locals[0]);
il.LoadLocal(locals[1]);
il.UnsignedBranchIfNotEqual(label);
il.Return();
@eventBuilder.SetAddOnMethod(methodBuilder);
}
if (removeMethod != null)
{
if (fieldBuilder == null)
{
fieldBuilder = typeBuilder.DefineField(@event.Name, @event.EventHandlerType, FieldAttributes.Private);
}
/*泛型方法和基本方法有什么不同*/
var parameters = removeMethod.GetParameters();
var parameterTypes = new List <Type>(parameters.Length);
var voidReturn = removeMethod.ReturnType == typeof(void);
foreach (var parameter in parameters)
{
parameterTypes.Add(parameter.ParameterType);
}
var attributes = MethodAttributes.Public | MethodAttributes.Virtual | MethodAttributes.HideBySig | MethodAttributes.SpecialName;
if (!buildInterface)
{
attributes = MethodAttributes.Public | MethodAttributes.ReuseSlot | MethodAttributes.Virtual | MethodAttributes.HideBySig;
}
var methodBuilder = typeBuilder.DefineMethod(removeMethod.Name,
attributes,
removeMethod.CallingConvention,
removeMethod.ReturnType, parameterTypes.ToArray());
/*fix argument length*/
parameterTypes.Insert(0, sourceTypeOrInterfaceType);
var il = new MockEmitBuilder(methodBuilder.GetILGenerator(), removeMethod.CallingConvention, removeMethod.ReturnType, parameterTypes.ToArray());
var locals = new[]
{
il.DeclareLocal(@event.EventHandlerType),
il.DeclareLocal(@event.EventHandlerType),
il.DeclareLocal(@event.EventHandlerType),
};
var label = il.DefineLabel();
il.LoadArgument(0);
il.LoadField(fieldBuilder);
il.StoreLocal(locals[0]);
il.MarkLabel(label);
il.LoadLocal(locals[0]);
il.StoreLocal(locals[1]);
il.LoadLocal(locals[1]);
il.LoadArgument(1);
MethodInfo delegateMethod = null;
foreach (var method in typeof(System.Delegate).GetMethods(BindingFlags.Public | BindingFlags.Static))
{
if (method.Name == "Remove" && method.GetParameters().Length == 2)
{
delegateMethod = method;
break;
}
}
il.Call(delegateMethod);
il.CastClass(@event.EventHandlerType);
il.StoreLocal(locals[2]);
il.LoadArgument(0);
il.LoadFieldAddress(fieldBuilder);
il.LoadLocal(locals[2]);
il.LoadLocal(locals[1]);
foreach (var method in typeof(System.Threading.Interlocked).GetMethods(BindingFlags.Public | BindingFlags.Static))
{
if (method.Name == "CompareExchange" && method.IsGenericMethod && method.GetParameters().Length == 3)
{
delegateMethod = method;
break;
}
}
il.Call(delegateMethod.MakeGenericMethod(new[] { @event.EventHandlerType }));
il.StoreLocal(locals[0]);
il.LoadLocal(locals[0]);
il.LoadLocal(locals[1]);
il.UnsignedBranchIfNotEqual(label);
il.Return();
@eventBuilder.SetRemoveOnMethod(methodBuilder);
}
}
