SharePoint: Make a list field Required programmatically

Question

I have a list and one of the list field is of managed meta data field type.It has to be a required field on the list.I would not set the Required attribute to true in the XML file, as other lists in the project use it as a optional field.Searched many articles, none of them helped .

Note: Field.Required=true; Field.Update(); Doesn't make the field as required field Field is not part of content type

Any ideas on this are appreciated..

Thanks

Answer 1

Is the field a part of a contenttype? In that case you might want to get a reference to the fieldlink and set that as required:

var myField = list.Fields["MyFieldName"];
var ct = list.Contenttypes["MyContentType"];

var fieldLink = ct.FieldLinks[myField];
fieldLink.Required = true;
ct.Update();

Answer 2

Try this

`

SPField field = list.Fields["MyField"]; 
field.Required= true;
field.Update();
list.Update();

`

Answer 3

Use sharepoint designer, select the list, a listing of columns will be displayed.

Double click the column and within the Column Editor popup uncheck "Allow blank Values?". Save and test...field should now be mandatory.