static object DoCreate(ModuleBuilder mb, Type t)
{
NativeDllAttribute[] dllAttributes = (NativeDllAttribute[])t.GetCustomAttributes(typeof(NativeDllAttribute), false);
if (dllAttributes.Length == 0)
{
throw new Exception("Interface must be marked with CK.Interop.NativeDllAttribute.");
}
string defaultDllName = dllAttributes[0].GetBestDefaultName();
TypeBuilder type = mb.DefineType(String.Format("CK_Dyn_{0}_{1}", t.Name, ++_countName));
type.AddInterfaceImplementation(t);
foreach (MethodInfo m in t.GetMethods())
{
DllImportAttribute a = (DllImportAttribute)Attribute.GetCustomAttribute(m, typeof(DllImportAttribute), false);
if (a != null)
{
// DllName
string dllName = a.GetBestDllName(defaultDllName);
// Extract parameters type.
Type[] parameterTypes = ReflectionHelper.CreateParametersType(m.GetParameters());
MethodBuilder nativeMethod = CreateNative(type, dllName, m, a, parameterTypes);
MethodBuilder method = type.DefineMethod(m.Name,
MethodAttributes.Public | MethodAttributes.Virtual,
m.ReturnType,
parameterTypes);
ILGenerator g = method.GetILGenerator();
g.RepushActualParameters(false, parameterTypes.Length);
g.EmitCall(OpCodes.Call, nativeMethod, null);
g.Emit(OpCodes.Ret);
}
}
Type finalType = type.CreateType();
return(Activator.CreateInstance(finalType));
}
private static MethodBuilder CreateNative(TypeBuilder tb, string dllName, MethodInfo m, DllImportAttribute a, Type[] parameterTypes)
{
// This code is from msdn itself (the example associated to TypeBuilder.DefinePInvokeMethod).
MethodBuilder native = tb.DefineMethod("_st_" + m.Name, MethodAttributes.Private | MethodAttributes.Static | MethodAttributes.HideBySig, m.ReturnType, parameterTypes);
// Create an array of values to assign to the fields of the
// DLLImportAttribute class, when constructing an attribute
// for the native function.
object[] fieldvalues = new object[]
{
a.GetBestEntryPoint(m.Name),
a.ExactSpelling,
a.PreserveSig,
a.SetLastError,
a.CallingConvention,
a.CharSet,
a.BestFitMapping,
a.ThrowOnUnmappableChar
};
// Construct a DLLImportAttribute.
CustomAttributeBuilder attr = new CustomAttributeBuilder(_impAttrCtor, new object[] { dllName }, _impAttrFields, fieldvalues);
// Apply the DLLCustomAttribute to the PInvoke method.
native.SetCustomAttribute(attr);
// The PInvoke method does not have a method body.
return(native);
}