How to get target methodinfo from a delegate

There is a express x=> x.delegate += null, how to get target methodinfo from this express. I know by il file , but it's not so friendly,

anyone has any reasonable solution?

EventInfo GetTargetMethodInfo(Delegate d)
{
    EventInfo info = null;
    var ilBytes = d.Method.GetMethodBody().GetILAsByteArray();
    var callIdx = Array.IndexOf(ilBytes, (Byte)OpCodes.Ldnull.Value);
    var calledMethodEntry = Array.FindIndex(ilBytes, x => x == OpCodes.Callvirt.Value || x == OpCodes.Call.Value);
    if (callIdx > 0 && callIdx < ilBytes.Length
        && calledMethodEntry > callIdx)
    {
        var pos = calledMethodEntry + 1;
        var methodCode = (((ilBytes[pos++] | (ilBytes[pos++] << 8)) | (ilBytes[pos++] << 0x10)) | (ilBytes[pos++] << 0x18));

        var mi = d.Method.Module.ResolveMethod(methodCode);
        if (mi != null && mi.Name.StartsWith("add_"))
        {
            var evtName = mi.Name.Substring(4);
            info = mi.DeclaringType.GetEvent(evtName);
        }
    }
    return info;
}