The ID is still there, even in a dialog. The dialog opens in an iframe, so you can still look at the Query String.
For example, the iframe might contain:
https://servername/Lists/Contacts/EditForm.aspx?ID=1&ContentTypeId=0x010600E5C9FE5FB4E59644BE10ECCC918E2E82&IsDlg=1
M.
For example, the iframe might contain:
https://servername/Lists/Contacts/EditForm.aspx?ID=1&ContentTypeId=0x010600E5C9FE5FB4E59644BE10ECCC918E2E82&IsDlg=1
M.