How do you remove fields from a custom list in SharePoint that have been added via the 'Add from existing site columns' menu item?

Question

I have a custom list, and I've added a 'Page Image' field by clicking on the 'Add from existing site columns' link on the Settings page for the list. I would now like to remove the field, but clicking on the field name on the Settings page yields no 'Delete' functionality.

Answer 1

"Page Image" is a special kind of SharePoint field defined as Sealed. This means it cannot be removed from the UI once added. However it can be removed programmatically:

SPList list = web.Lists["CustomTest"];
SPField f = list.Fields["Page Image"];
f.Sealed = false;
f.Update();
f.Delete();

For reference, the field is defined in C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\FEATURES\PublishingResources\PublishingColumns.xml.

^{_{Attribution credit: my answer on Stack Overflow.}}

Answer 2

Besides being Sealed, a field can be read-only, hidden and etc. All these factors might prevent the field from deletion. The more suitable method to delete a list field is the following one:

public static bool RemoveField(SPField spField)
{
    if (spField == null)
    {
        WriteErrorToLog("spField is null! Please, provide a valid one");
        return false;
    }

    bool res = false;
    try
    {
        // check if it's a ReadOnly field.
        // if so, reset it
        if (spField.ReadOnlyField)
        {
            spField.ReadOnlyField = false;
            spField.Update();
        }

        // check if it's a Hidden field.
        // if so, reset it
        if (spField.Hidden)
        {
            spField.Hidden = false;
            spField.Update();
        }

        // check if the AllowDeletion property is set to false.
        // if so, reset it to true
        if (spField.AllowDeletion == null || !spField.AllowDeletion.Value)
        {
            spField.AllowDeletion = true;
            spField.Update();
        }

        // If the AllowDeletion property is set,
        // the Sealed property seems not to be examined at all.
        // So the following piece of code is commented.
        /*if(spField.Sealed)
        {
            spField.Sealed = false;
            spField.Update();
        }*/

        // If the AllowDeletion property is set,
        // the FromBaseType property seems not to be examined at all.
        // So the following piece of code is commented.
        /*if(spField.FromBaseType)
        {
            spField.FromBaseType = false;
            spField.Update();
        }*/

        // finally, remove the field
        spField.Delete();
        spField.ParentList.Update();

        res = true;
    }
    catch (Exception ex)
    {
        WriteErrorToLog(ex.Message);
    }

    return res;
}

public static bool RemoveField(SPList spList, string displayNameOrInternalNameOrStaticName)
{
    SPField spField = GetFieldByName(spList, displayNameOrInternalNameOrStaticName);
    if(spField == null)
    {
        WriteErrorToLog(string.Format("Couldn't find field {0}!", displayNameOrInternalNameOrStaticName));
        return false;
    }

    return RemoveField(spField);
}

public static void WriteErrorToLog(string errorMsg)
{
    // write error into log
}

Read my article How to Delete a List Field/Column programmatically, to learn more.

Answer 3

I have seen this before when you add fields that SharePoint consider non-deletable.

You will probably have to delete it programmatically or a tool like SharePointManager

Answer 4

How about hiding the field using manage content types?

List Settings --> Advanced Settings -->Allow Manage content types Click on COntent Type --> click on Page Image field --> Select Hidden?

Answer 5

1. First go to Home option in Default Page
2. Click on list name that you have created.
3. Click on List setting option in setting tab pane.
4. Click on Column name in Columns option
5. Then you get the option to delete. Press it and it will be deleted.