AvaloniaUI/Avalonia · error · FormatException

Too many provided values.

Error message

Too many provided values.

What it means

Thrown inside TransformParser.ParseCommaDelimitedValues when the number of comma-separated values in a transform function argument list exceeds the capacity of the output span (outValues). Each transform function expects a fixed maximum number of arguments; supplying more than that triggers this FormatException.

Source

Thrown at src/Avalonia.Base/Media/Transformation/TransformParser.cs:157

                    rightValue = ParseValue(rightPart);

                    return 2;
                }

                leftValue = ParseValue(part);

                return 1;
            }

            static int ParseCommaDelimitedValues(ReadOnlySpan<char> part, in Span<UnitValue> outValues)
            {
                int valueIndex = 0;

                while (true)
                {
                    if (valueIndex >= outValues.Length)
                    {
                        throw new FormatException("Too many provided values.");
                    }

                    var commaIndex = part.IndexOf(',');

                    if (commaIndex == -1)
                    {
                        if (!part.IsWhiteSpace())
                        {
                            outValues[valueIndex++] = ParseValue(part);
                        }

                        break;
                    }

                    var valuePart = part.Slice(0, commaIndex).Trim();

                    outValues[valueIndex++] = ParseValue(valuePart);

View on GitHub (pinned to 11c5427268)

Solutions

1. Check the expected argument count for the transform function and remove extras.
2. Refer to the function's documented value count (reported separately via error 327) to match the call.
3. If a 3D transform is needed, confirm the platform/build supports it or use the appropriate 3D-capable API.

Example fix

// before
var t = TransformOperations.Parse("translate(10px, 20px, 30px)"); // too many values

// after
var t = TransformOperations.Parse("translate(10px, 20px)");

try { return TransformOperations.Parse(s); }
catch (FormatException) { /* fix arg count and retry */ }

When it happens

Trigger: Providing a transform function with too many comma-delimited arguments, e.g. translate(10px, 20px, 30px) when the function only accepts two. The parser iterates values and, once valueIndex reaches outValues.Length, it throws 'Too many provided values.'

Common situations: Hand-authored CSS/XAML transforms with extra arguments; copy-pasting a 3D transform (translate3d, scale3d) into a 2D-only context; misunderstanding the argument count a given function accepts.

Related errors

• Invalid format. {function} expects {count} value(s).
• Invalid transform string: '{s}'.
• Invalid value {value.Value} {unitString} for {function}
• Invalid unit: {part.ToString()}
• Invalid text trimming string: '{s}'.

AI-assisted analysis of AvaloniaUI/Avalonia@11c5427268 (2026-08-13). Data as JSON: /api/errors/060d828d57925cfc. Report an issue: GitHub.