dotnet/wpf · error · ArgumentOutOfRangeException

ArgumentOutOfRangeException(percentageWithinBounds)

Error message

ArgumentOutOfRangeException(percentageWithinBounds)

What it means

StrokeCollection.HitTest(Rect, int percentageWithinBounds) requires percentageWithinBounds to be between 0 and 100 inclusive; other values throw ArgumentOutOfRangeException naming percentageWithinBounds. It controls what fraction of a stroke must lie inside the rectangle for a hit.

Solutions

Clamp: Math.Clamp(percentageWithinBounds, 0, 100) before the call
Convert fractions to percentages before passing
Validate the value in the settings/UI layer that produces it

Example fix

// before
var hits = strokes.HitTest(rect, conf); // conf in 0..1
// after
var hits = strokes.HitTest(rect, Math.Clamp((int)(conf * 100), 0, 100));

Defensive patterns

Strategy: validation

Validate before calling

int pct = Math.Clamp(percentageWithinBounds, 0, 100);

Try / catch

try { return strokes.HitTest(bounds, pct); } catch (ArgumentOutOfRangeException) { return new StrokeCollection(); }

Prevention

Clamp percentage inputs once in a shared helper
Validate persisted settings at load time
Use the same conversion path as the lasso overload to avoid unit drift

When it happens

Trigger: Calling the rectangle HitTest overload with a negative or >100 percentage, typically a 0-1 fraction passed directly or an unclamped user setting.

Common situations: Same unit-confusion as the lasso overload: normalized confidence values, sliders configured with the wrong range, or arithmetic producing values above 100.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/3cb64a37aa9a59b2. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Ink/StrokeCollection2.cs:151

            // Return the resulting collection
            return lassoedStrokes;
        }


        /// <summary>
        /// Hit-testing with rectangle
        /// </summary>
        /// <param name="bounds">hitting rectangle</param>
        /// <param name="percentageWithinBounds">the percentage of the stroke that must be within 
        /// the bounds to be considered hit</param>
        /// <returns>collection of strokes found inside the rectangle</returns>
        public StrokeCollection HitTest(Rect bounds, int percentageWithinBounds)
        {
            // Check the input parameters
            if ((percentageWithinBounds < 0) || (percentageWithinBounds > 100))
            {
                throw new System.ArgumentOutOfRangeException(nameof(percentageWithinBounds));
            }
            if (bounds.IsEmpty)
            {
                return new StrokeCollection();
            }

            // Enumerate thru the strokes collect those found within the rectangle.
            StrokeCollection hits = new StrokeCollection();
            foreach (Stroke stroke in this)
            {
                // Presharp gives a warning when get methods might deref a null.  It's complaining
                // here that 'stroke'' could be null, but StrokeCollection never allows nulls to be added
                // so this is not possible
                if (stroke.HitTest(bounds, percentageWithinBounds))
                {
                    hits.Add(stroke);
                }
            }

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