dotnet/wpf · error · InvalidEnumArgumentException

InvalidEnumArgumentException(direction, (int)direction…

Error message

InvalidEnumArgumentException(direction, (int)direction, typeof(ListSortDirection))

What it means

The SortDescription constructor validates that direction is exactly ListSortDirection.Ascending or Descending. Any other cast integer/enum value throws InvalidEnumArgumentException naming the 'direction' parameter, guarding against undefined sort directions.

Solutions

Pass only ListSortDirection.Ascending or ListSortDirection.Descending
Enum.IsDefined(typeof(ListSortDirection), value) before casting and constructing
Map legacy/unknown stored values to a valid direction with a default fallback

Example fix

// before
var sd = new SortDescription(prop, (ListSortDirection)rawValue);
// after
var dir = Enum.IsDefined(typeof(ListSortDirection), rawValue) ? (ListSortDirection)rawValue : ListSortDirection.Ascending;
var sd = new SortDescription(prop, dir);

Defensive patterns

Strategy: validation

Validate before calling

if (!Enum.IsDefined(typeof(ListSortDirection), direction)) throw new InvalidEnumArgumentException(nameof(direction), (int)direction, typeof(ListSortDirection));

Type guard

static bool IsValidSortDirection(ListSortDirection d) => d == ListSortDirection.Ascending || d == ListSortDirection.Descending;

Try / catch

try { var sd = new SortDescription(name, dir); } catch (InvalidEnumArgumentException) { dir = ListSortDirection.Ascending; }

Prevention

Never cast raw ints to ListSortDirection without Enum.IsDefined
Persist sort directions as enum names, not numbers
Clamp deserialized values to Ascending by default

When it happens

Trigger: new SortDescription("Name", (ListSortDirection)2) or passing an int-cast/unknown enum value from config, data binding, or deserialization.

Common situations: Deserializing sort settings from XML/JSON where the stored integer no longer matches the enum; bitwise-combining enum values incorrectly; cross-version enum changes.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/2d1c16e793e89705. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/WindowsBase/System/ComponentModel/SortDescription.cs:28

    {
        //------------------------------------------------------
        //
        //  Public Constructors
        //
        //------------------------------------------------------

        #region Public Constructors

        /// <summary>
        /// Create a sort description.
        /// </summary>
        /// <param name="propertyName">Property to sort by</param>
        /// <param name="direction">Specifies the direction of sort operation</param>
        /// <exception cref="InvalidEnumArgumentException"> direction is not a valid value for ListSortDirection </exception>
        public SortDescription(string propertyName, ListSortDirection direction)
        {
            if (direction != ListSortDirection.Ascending && direction != ListSortDirection.Descending)
                throw new InvalidEnumArgumentException("direction", (int)direction, typeof(ListSortDirection));

            _propertyName = propertyName;
            _direction = direction;
            _sealed = false;
        }

        #endregion Public Constructors


        //------------------------------------------------------
        //
        //  Public Properties
        //
        //------------------------------------------------------

        #region Public Properties

        /// <summary>

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