dotnet/wpf · error · ArgumentException

SR.Format(SR.Color_DimensionMismatch, null)

Error message

SR.Format(SR.Color_DimensionMismatch, null)

What it means

Color.FromAValues builds a non-sRGB color from a channel-values array that must match the channel count of the color context/profile identified by profileUri. This ArgumentException is thrown when the values array is null — no channel data was supplied.

Solutions

1. Pass a non-null float[] with one element per channel of the profile
2. Initialize the array with defaults (e.g. zeros) when data is unavailable
3. Validate the array for null before calling FromAValues

Example fix

// before
 Color c = Color.FromAValues(1.0f, null, profileUri);
// after
 Color c = Color.FromAValues(1.0f, new float[] {0.5f, 0.5f, 0.5f}, profileUri);

if (values == null) throw new InvalidOperationException("channel values required before Color.FromAValues");

bool HasChannelValues(float[] values) => values != null && values.Length > 0;

try { var c = Color.FromAValues(a, values, uri); } catch (ArgumentException ex) { /* values was null or wrong dimension */ }

When it happens

Trigger: Calling Color.FromAValues(a, null, profileUri) — passing null for the float[] values parameter.

Common situations: Binding the values array to data that has not been loaded yet; refactoring code where the array became optional; conditional construction paths that skip array initialization.

Related errors

• anchorLocator.Parts
• ArgumentNullException (buffer/sourceBuffer was IntPtr.Zero)
• ArgumentNullException: handle
• ArgumentNullException(nameof(assemblyName))
• ArgumentNullException(nameof(assemblyNames))

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/0a97567143a2de63. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Color.cs:70

                    c1.nativeColorValue[i] = 0.0f;
                }
            }

            c1.isFromScRgb = false;

            return c1;
        }

        ///<summary>
        /// FromAValues - general constructor for multichannel color values with explicit alpha channel and color context, i.e. spectral colors
        ///</summary>
        public static Color FromAValues(float a, float[] values, Uri profileUri)
        {
            Color c1 = Color.FromProfile(profileUri);

            if (values == null)
            {
                throw new ArgumentException(SR.Format(SR.Color_DimensionMismatch, null));
            }

            if (values.Length != c1.nativeColorValue.Length)
            {
                throw new ArgumentException(SR.Format(SR.Color_DimensionMismatch, null));
            }

            for (int numChannels = 0; numChannels < values.Length; numChannels++)
            {
                c1.nativeColorValue[numChannels] = values[numChannels];
            }
            c1.ComputeScRgbValues();
            c1.scRgbColor.a = a;
            if (a < 0.0f)
            {
                a = 0.0f;
            }
            else if (a > 1.0f)

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