How to set field readonly in one content type only?

Question

In a list with two content types - both with the same field "Title", I need to make the field readonly in one of the content types, but not the other (in one the title is manually set, in the other the title is set by code).

Is this possible?

Answer 1

You can do this in PowerShell as follows:

$fieldLink = $list.ContentTypes["YourCT"].FieldLinks | where {$_.Name -eq "YourField"}
$fieldLink.ReadOnly = $true
$list.ContentTypes["YourCT"].Update()