public static bool TryCastDelegate(this Delegate source, Type type, out Delegate result)
{
result = null;
if (source == null)
{
return(false);
}
try {
Delegate[] delegates = source.GetInvocationList();
if (delegates.Length == 1)
{
result = NETStandardShims.CreateDelegate(type, delegates[0].Target, delegates[0].GetMethodInfo());
return(true);
}
Delegate[] delegatesDest = new Delegate[delegates.Length];
for (int i = 0; i < delegates.Length; i++)
{
delegatesDest[i] = delegates[i].CastDelegate(type);
}
result = Delegate.Combine(delegatesDest);
return(true);
} catch {
return(false);
}
}
public static void ModInterop(this Type type)
{
if (Registered.Contains(type))
{
return;
}
Registered.Add(type);
string prefix = type.GetTypeInfo().Assembly.GetName().Name;
foreach (ModExportNameAttribute attrib in type.GetTypeInfo().GetCustomAttributes(typeof(ModExportNameAttribute), false))
{
prefix = attrib.Name;
}
// Collect fields and methods in the type.
foreach (FieldInfo field in type.GetTypeInfo().GetFields(BindingFlags.Public | BindingFlags.Static))
{
if (!typeof(Delegate).GetTypeInfo().IsAssignableFrom(field.FieldType))
{
continue;
}
Fields.Add(field);
}
foreach (MethodInfo method in type.GetTypeInfo().GetMethods(BindingFlags.Public | BindingFlags.Static))
{
method.RegisterModExport();
method.RegisterModExport(prefix);
}
// Refresh all existing fields and methods.
foreach (FieldInfo field in Fields)
{
List <MethodInfo> methods;
if (!Methods.TryGetValue(field.GetModImportName(), out methods))
{
field.SetValue(null, null);
continue;
}
// Set the field to the first matching method, or null.
bool matched = false;
foreach (MethodInfo method in methods)
{
try {
field.SetValue(null, NETStandardShims.CreateDelegate(field.FieldType, null, method));
matched = true;
break;
} catch {
// Silently try the next method with the same name.
}
}
if (!matched)
{
field.SetValue(null, null);
}
}
}
/// <summary>
/// Cast a delegate from one type to another. Compatible with delegates holding an invocation list (combined delegates).
/// </summary>
/// <param name="source">The input delegate.</param>
/// <param name="type">The wanted output delegate type.</param>
/// <returns>The output delegate.</returns>
public static Delegate CastDelegate(this Delegate source, Type type)
{
if (source == null)
{
return(null);
}
Delegate[] delegates = source.GetInvocationList();
if (delegates.Length == 1)
{
return(NETStandardShims.CreateDelegate(type, delegates[0].Target, delegates[0].GetMethodInfo()));
}
Delegate[] delegatesDest = new Delegate[delegates.Length];
for (int i = 0; i < delegates.Length; i++)
{
delegatesDest[i] = delegates[i].CastDelegate(type);
}
return(Delegate.Combine(delegatesDest));
}