mika kuns
56f7d64f07
Clearing the text box to type a new value sets Value to null, which the TwoWay binding then wrote into an int/decimal target -- InvalidCastException on the normal way of editing eight settings fields. KeepLastNumberConverter maps that null to BindingOperations.DoNothing so the source keeps its last value.
25 lines
1.1 KiB
C#
25 lines
1.1 KiB
C#
using System.Globalization;
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using Avalonia.Data;
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using Avalonia.Data.Converters;
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namespace ClaudeDo.Ui.Converters;
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/// <summary>
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/// For <c>NumericUpDown.Value</c> bound to a non-nullable numeric property. The control's Value is
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/// <c>decimal?</c> and goes null the moment the text box is empty — which is exactly what happens
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/// while the user clears a value to type a new one. Writing that null into an <c>int</c>/<c>decimal</c>
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/// target throws <see cref="InvalidCastException"/>, so swallow it and leave the source untouched
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/// until a real number arrives.
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/// </summary>
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public class KeepLastNumberConverter : IValueConverter
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{
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public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
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=> value is null ? null : System.Convert.ToDecimal(value, culture);
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public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
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{
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if (value is null) return BindingOperations.DoNothing;
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return System.Convert.ChangeType(value, Nullable.GetUnderlyingType(targetType) ?? targetType, culture);
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}
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}
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