dotnet/wpf · error · ArgumentException

SR.Timing_InvalidArgAccelAndDecel

Error message

SR.Timing_InvalidArgAccelAndDecel

What it means

Timeline.AccelerationRatio and Timeline.DecelerationRatio validate their value through ValidateAccelerationDecelerationRatio, which requires a double in [0, 1] that is not NaN. Values outside that range throw ArgumentException with Timing_InvalidArgAccelAndDecel.

Solutions

  1. Clamp before assigning: Math.Max(0, Math.Min(1, value)).
  2. Default NaN to 0 before assigning.
  3. In XAML/data binding, restrict the source value to [0,1] (slider Maximum=1) or add a conversion step.

Example fix

// before
timeline.AccelerationRatio = userPercent; // e.g. 50
// after
timeline.AccelerationRatio = Math.Clamp(userPercent / 100.0, 0.0, 1.0);
Defensive patterns

Strategy: validation

Validate before calling

double v = double.IsNaN(ratio) ? 0 : Math.Clamp(ratio, 0.0, 1.0);
timeline.AccelerationRatio = v;

Type guard

static bool IsValidAccelDecelRatio(double v) => !double.IsNaN(v) && v >= 0 && v <= 1;
static double SafeRatio(double v) => double.IsNaN(v) ? 0 : Math.Clamp(v, 0.0, 1.0);

Try / catch

try { timeline.AccelerationRatio = ratio; }
catch (ArgumentException) { timeline.AccelerationRatio = 0; }

Prevention

When it happens

Trigger: timeline.AccelerationRatio = 1.5, = -0.1, or = double.NaN. Also triggered by data binding to a computed property that returns a value outside 0..1.

Common situations: Computing the ratio as a percentage (e.g., 50 instead of 0.5); dividing by zero producing NaN; user input from a slider allowing values > 1; config values stored as percents.

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/d61e43804731f8f8. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Animation/Timeline.cs:212

        public double AccelerationRatio
        {
            get
            {
                return (double)GetValue(AccelerationRatioProperty);
            }
            set
            {
                SetValue(AccelerationRatioProperty, value);
            }
        }

        private static bool ValidateAccelerationDecelerationRatio(object value)
        {
            double newValue = (double)value;

            if (newValue < 0 || newValue > 1 || double.IsNaN(newValue))
            {
                throw new ArgumentException(SR.Timing_InvalidArgAccelAndDecel, nameof(value));
            }

            return true;
        }

        #endregion // AccelerationRatio Property


        #region AutoReverse Property

        /// <summary>
        /// AutoReverseProperty
        /// </summary>
        public static readonly DependencyProperty AutoReverseProperty =
            DependencyProperty.Register(
                "AutoReverse",
                typeof(bool),
                typeof(Timeline),

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