dotnet/wpf · error · ArgumentException

SR.InvalidCursorType (cursorType)

Error message

SR.InvalidCursorType (cursorType)

What it means

The Cursor(CursorType) constructor checks IsValidCursorType and throws ArgumentException (SR.InvalidCursorType) when the CursorType value is not a valid Win32-supported cursor type. Only a subset of CursorType members are loadable as system cursors.

Solutions

1. Use Cursors.AppStarting/Cursors.Wait etc. predefined static cursors instead of constructing from CursorType.
2. Only construct with CursorType members known valid (Arrow, Wait, Cross, Hand, IBeam, SizeAll, etc.).
3. Validate with Enum.IsDefined and a whitelist of supported types before constructing.

Example fix

// before
this.Cursor = new Cursor((CursorType)storedValue);
// after
this.Cursor = Cursors.Wait; // or validate storedValue against a whitelist first

var valid = new HashSet<CursorType>{ CursorType.Arrow, CursorType.Wait, CursorType.Cross, CursorType.Hand, CursorType.IBeam, CursorType.SizeAll };
if (valid.Contains(type)) this.Cursor = new Cursor(type);

static bool IsValidCursorTypeValue(CursorType c) => Enum.IsDefined(typeof(CursorType), c);

try { this.Cursor = new Cursor(type); } catch (ArgumentException ex) { this.Cursor = Cursors.Arrow; }

When it happens

Trigger: new Cursor((CursorType)outOfRangeInt) or new Cursor(CursorType member not supported by LoadCursorHelper, e.g. values outside the standard system cursor set).

Common situations: Restoring cursor selection from an int saved in settings, or iterating CursorType enum values assuming all are valid constructor inputs.

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

• ArgumentOutOfRangeException (timeout was Duration.Automatic)
• Collection_BadRank
• Collection_CopyTo_ArrayCannotBeMultidimensional
• Collection_CopyTo_ArrayCannotBeMultidimensional
• Collection_CopyTo_IndexGreaterThanOrEqualToArrayLength

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/0d486d5c5a84ce2d. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/Cursor.cs:32

    /// </summary>
    [TypeConverter(typeof(CursorConverter))]
    [Localizability(LocalizationCategory.None, Readability = Readability.Unreadable)]
    public sealed class Cursor : IDisposable
    {
        /// <summary>
        /// Constructor for Standard Cursors, needn't be public as Stock Cursors
        /// are exposed in Cursors clas.
        /// </summary>
        /// <param name="cursorType"></param>
        internal Cursor(CursorType cursorType)
        {
            if (IsValidCursorType(cursorType))
            {
                LoadCursorHelper(cursorType);
            }
            else
            {
                throw new ArgumentException(SR.Format(SR.InvalidCursorType, cursorType));
            }
        }

        /// <summary>
        /// Cursor from .ani or .cur file
        /// </summary>
        /// <param name="cursorFile"></param>
        public Cursor(string cursorFile):this(cursorFile, false)
        {
        }

        /// <summary>
        /// Cursor from .ani or .cur file
        /// </summary>
        /// <param name="cursorFile"></param>
        /// <param name="scaleWithDpi"></param>
        public Cursor(string cursorFile, bool scaleWithDpi)
        {

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