stride3d/stride · error · ArgumentNullException

text

Error message

text

What it means

SpriteFont.MeasureString(string, ref Vector2, int) throws ArgumentNullException when the text string is null. Measuring requires iterating the characters to compute the layout size; null is rejected at the entry point. An empty string is valid and yields a zero-size measurement.

Solutions

1. Pass string.Empty for absent text — MeasureString(empty) returns a zero-size Vector2
2. Guard: if (text != null) var size = font.MeasureString(text, ...)
3. Coalesce with ?? string.Empty at the call site
4. Fix the text provider (localization, data binding) so it never returns null

Example fix

// before
var size = font.MeasureString(text, ref fontSize, text.Length); // text may be null
// after
var size = font.MeasureString(text ?? string.Empty, ref fontSize, (text ?? string.Empty).Length);

var safeText = text ?? string.Empty;
var size = font.MeasureString(safeText, ref fontSize, safeText.Length);

static bool CanMeasure(string s) => s != null;

try { size = font.MeasureString(text, ref fontSize, len); }
catch (ArgumentNullException) { size = Vector2.Zero; }

When it happens

Trigger: Calling MeasureString with a null string, e.g. measuring text loaded from a data source that returned null, or forwarding an optional UI label value before it is set.

Common situations: Localization lookup returning null for a missing key; measuring a player/ itemName that is null until data loads; computing layout for a label whose Text property was never initialized.

Related errors

• text
• [ ] cannot be null in
• [ ] cannot be null in
• [ ] cannot be null in
• [ ] cannot be null in

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/0b3f442ab6e3cd92. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Graphics/SpriteFont.cs:446

        /// <param name="fontSize">The size of the font (ignored in the case of static fonts)</param>
        /// <param name="length">The length of the string to measure</param>
        /// <returns>Vector2.</returns>
        public Vector2 MeasureString([NotNull] StringBuilder text, Vector2 fontSize, int length)
        {
            return MeasureString(text, ref fontSize, length);
        }

        /// <summary>
        /// Returns the width and height of the provided text for a given font size
        /// </summary>
        /// <param name="text">The string to measure.</param>
        /// <param name="fontSize">The size of the font (ignored in the case of static fonts)</param>
        /// <param name="length">The length of the string to measure</param>
        /// <returns>Vector2.</returns>
        public Vector2 MeasureString([NotNull] string text, ref Vector2 fontSize, int length)
        {
            if (text == null)
                throw new ArgumentNullException(nameof(text));

            var proxy = new StringProxy(text, length);
            return MeasureString(proxy, fontSize);
        }

        /// <summary>
        /// Returns the width and height of the provided text for a given font size
        /// </summary>
        /// <param name="text">The string to measure.</param>
        /// <param name="fontSize">The size of the font (ignored in the case of static fonts)</param>
        /// <param name="length">The length of the string to measure</param>
        /// <returns>Vector2.</returns>
        public Vector2 MeasureString([NotNull] StringBuilder text, ref Vector2 fontSize, int length)
        {
            if (text == null)
                throw new ArgumentNullException(nameof(text));

            var proxy = new StringProxy(text, length);

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