dotnet/wpf · error · ArgumentOutOfRangeException

SeekOrigin value is not valid.

Error message

SeekOrigin value is not valid.

What it means

NetStream.Seek switches on the SeekOrigin parameter (Begin/Current/End); any value outside these three hits the default case and throws ArgumentOutOfRangeException. This library throws it because only the three standard origins are defined.

Solutions

1. Pass only SeekOrigin.Begin, SeekOrigin.Current, or SeekOrigin.End
2. Validate the origin against Enum.IsDefined(typeof(SeekOrigin), value) before calling Seek
3. If a custom origin is needed, compute the absolute offset yourself and use SeekOrigin.Begin

Example fix

// before
stream.Seek(delta, (SeekOrigin)myInt);
// after
var origin = Enum.IsDefined(typeof(SeekOrigin), myInt) ? (SeekOrigin)myInt : SeekOrigin.Begin;
stream.Seek(delta, origin);

if (!Enum.IsDefined(typeof(SeekOrigin), origin))
    throw new ArgumentException($"Invalid SeekOrigin: {origin}");
stream.Seek(offset, origin);

static bool IsDefinedSeekOrigin(SeekOrigin o) => o is SeekOrigin.Begin or SeekOrigin.Current or SeekOrigin.End;

try { stream.Seek(offset, origin); } catch (ArgumentOutOfRangeException ex) when (ex.ParamName == "origin") { origin = SeekOrigin.Begin; stream.Seek(offset, origin); }

When it happens

Trigger: Calling Seek(long offset, SeekOrigin origin) with an invalid (cast or uninitialized) origin value such as (SeekOrigin)3 or default(SeekOrigin) in non-zero-based code paths.

Common situations: Storing the origin in an int/byte field and casting it back after refactoring; passing a value read from configuration; enum extensions not supported by SeekOrigin (e.g. custom 'Start' origin).

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

• Cannot set seek pointer to a negative position.
• SeekOrigin value is not valid.
• SR.SeekNegative
• SR.SeekOriginInvalid
• A read or write operation references a location outside the…

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/f6061064c27668b1. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/IO/Packaging/NetStream.cs:250

                            temp = offset;
                            break;
                        }

                    case SeekOrigin.Current:
                        {
                            temp = _position + offset;
                            break;
                        }

                    case SeekOrigin.End:
                        {
                            temp = Length + offset;
                            break;
                        }

                    default:
                        {
                            throw new ArgumentOutOfRangeException(nameof(origin), SR.SeekOriginInvalid);
                        }
                }
            }
            if (temp < 0)
            {
                throw new ArgumentException(SR.SeekNegative);
            }

#if DEBUG
            if (System.IO.Packaging.PackWebRequestFactory._traceSwitch.Enabled)
                System.Diagnostics.Trace.TraceInformation("NetStream.Seek() pos:{0}", temp);
#endif
            _position = temp;
            return _position;
        }


        /// <summary>

View on GitHub (pinned to 81131a70a4)