Looking for code that will make certain columns read only

Question

I have 4 date columns in a list that need to be read only after the record is created. Does any one have code to do this?

Answer 1

I've used the following approach. You can define your own column based on DateTime column and define a custom field control. There you can use the control derived from the original control for the DateTime field and set the control mode to Display:

// Custom field class
public class SPFieldDateTimeReadOnly : SPFieldDateTime
    {
        public SPFieldDateTimeReadOnly(SPFieldCollection fields, string fieldName) : base(fields, fieldName)
        {

        }

        public SPFieldDateTimeReadOnly(SPFieldCollection fields, string typeName, string displayName) : base(fields, typeName, displayName)
        {

        }

        public override BaseFieldControl FieldRenderingControl
        {
            get { return new DateTimeFieldReadonly(); }
        }
    }

    // Custom field control class
    public class DateTimeFieldReadonly : DateTimeField
    {
        protected override void CreateChildControls()
        {
            // Here's all the magic
            ControlMode = SPControlMode.Display;

            base.CreateChildControls();
        }
    }

Answer 2

You can add event receiver: OnItemUpdating end cancel properties updating.

public class MyEventReceiver : SPItemEventReceiver
    {
       public override void ItemUpdating(SPItemEventProperties properties)
       {
           string myDateColumnName = "date1";
           properties.AfterProperties[myDateColumnName] =
           SPUtility.CreateISO8601DateTimeFromSystemDateTime((DateTime)properties.ListItem[myDateColumnName]);
       base.ItemUpdating(properties);
       }

Answer 3

Adding to what BioGeneZ said, you can hide the the field to show up in editform, so users will never see the field to update

$web = Get-SPWeb "http://test"
$list = $web.Lists["listname"]
$fields = $list.Fields.GetFieldByInternalName("nameofcolumn")
$field.ShowInEditForm = $false
$web.Dispose()