dotnet/wpf · error · ArgumentException

SR.GlyphTypefaceNotRecorded

Error message

SR.GlyphTypefaceNotRecorded

What it means

FontEmbeddingManager.GetUsedGlyphs throws this ArgumentException when the supplied glyphTypeface Uri was never recorded by a previous CollectGlyphTypefaces/embedding pass, so _collectedGlyphTypefaces contains no entry (or the stored entry is null). The method can only report glyphs for typefaces the manager has actually collected.

Solutions

  1. Ensure the glyph typefaces were collected first (render/layout text through the manager) before calling GetUsedGlyphs.
  2. Use the exact same glyphTypeface Uri that was recorded during collection.
  3. Check the Uri equals the keys recorded (scheme/casing differences produce different dictionary keys).

Example fix

// before
var mgr = new FontEmbeddingManager();
var glyphs = mgr.GetUsedGlyphs(fontUri); // never recorded
// after
var mgr = new FontEmbeddingManager();
mgr.CollectGlyphTypefaces(textSource...); // run collection
var glyphs = mgr.GetUsedGlyphs(fontUri);
Defensive patterns

Strategy: validation

Validate before calling

if (fontUri == null) throw new ArgumentNullException(nameof(fontUri));
// ensure collection happened; only query Uris produced by/used during collection

Try / catch

try { var glyphs = manager.GetUsedGlyphs(fontUri); }
catch (ArgumentException) { /* glyphTypeface was never recorded; run collection first */ }

Prevention

When it happens

Trigger: Calling GetUsedGlyphs(uri) with a Uri that was never passed to the manager's glyph-collection step (e.g. different Uri instance/equality, or GetUsedGlyphs called before any text layout occurred).

Common situations: Embedding workflows where the developer constructs a fresh FontEmbeddingManager and asks for used glyphs without first running the collection that populates the dictionary, or querying a font Uri that differs from the one actually used at render time.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/775a22eee1cb55ea. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/FontEmbeddingManager.cs:87

                return _collectedGlyphTypefaces.Keys;
            }
        }

        /// <summary>
        /// Obtain the list of glyphs used by the glyph typeface specified by a Uri.
        /// </summary>
        /// <param name="glyphTypeface">Specifies the Uri of a glyph typeface to obtain usage data for.</param>
        /// <returns>A collection of glyph indices recorded previously.</returns>
        /// <exception cref="System.ArgumentException">
        ///     Glyph typeface Uri does not point to a previously recorded glyph typeface.
        /// </exception>
        [CLSCompliant(false)]
        public ICollection<ushort> GetUsedGlyphs(Uri glyphTypeface)
        {
            Dictionary<ushort, bool> glyphsUsed = _collectedGlyphTypefaces[glyphTypeface];
            if (glyphsUsed == null)
            {
                throw new ArgumentException(SR.GlyphTypefaceNotRecorded, nameof(glyphTypeface));
            }
            return glyphsUsed.Keys;
        }

        #endregion Public Methods

        private class UriComparer : IEqualityComparer<Uri>
        {
            #region IEqualityComparer<Uri> Members

            public bool Equals(Uri x, Uri y)
            {
                // We don't use Uri.Equals because it doesn't compare Fragment parts,
                // and we use Fragment part to store font face index.
                return String.Equals(x.ToString(), y.ToString(), StringComparison.OrdinalIgnoreCase);
            }

            public int GetHashCode(Uri obj)

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