Field required in Content type, but not in my list

Question

I don't know why but when I try to bind a list with my content type, fields having a status to "Required" in my content type are not Required at all in my List.

I'm binding the field with this function :

function bindContentType($urlCollec, $xml, $lg){
Display-Info("Begin : Adding a Content Type")
$xmltypeContents = [xml](Get-Content $xml)
$typeContents = $xmltypeContents.contentTypes

foreach($typeContent in $typeContents.contentType){
    $url = $urlCollec+$typeContent.url
    $web = Get-SPWeb($url)

    $listTitle = GetValueByLanguage $lg $typeContent.list
    $list = $web.Lists[$listTitle]
    $webRoot = Get-SPWeb $urlCollection
    if($list -ne $null){
        $newCT = $webRoot.AvailableContentTypes[$typeContent.ctName]
        $list.ContentTypesEnabled = $true
        if($newCT -eq $null){
            Display-Error("The content type "+$typeContent.ctName+" does not exists")
        }
        else{
            # Add the content type to the list.
            if (!$list.IsContentTypeAllowed($newCT)){
                Display-Error("The content type is not allowed on the list")
            }
            elseif ($list.ContentTypes[$newCT.Name] -ne $null){
                Display-Warning("The content type name is already in use on the list");
            }
            else{
                $addingnewCt = $list.ContentTypes.Add($newCT);
                Display-Success("The content type "+$typeContent.ctName+" was successfully added to the list "+$listTitle);
            }

            $list.Update()
            if($typeContent.raz -eq 1)  {#Delete Associate type content 
                foreach($content in $list.ContentTypes){
                    if(!($content.Name -eq $typeContent.ctName)){
                        $list.ContentTypes.Delete($content.ID)

                    }
                }
            }
        }
    }
    else{
        Display-Error("The list "+$listTitle+" does not exists")
    }
}
Display-Info("End : Adding a Content Type ")
}

Do you have some ideas where it can come from ?

Thanks

Answer 1

Grab the web version of the content type, grab the FieldLink (FieldRef) and update that.

e.g. in pseudo code:-

SPContentType contentType = web.ContentTypes[contentTypeName];
SPField field = contentType.Fields[fieldName];
contentType.FieldLinks[field.Id].Required = true;
contentType.Update();