MultiTerm/MultiTerm.Wpf/ValueConverters/IntToStringConverter.cs

using System;
using System.Globalization;
using System.Windows.Data;

namespace MultiTerm.Wpf.ValueConverters;

public class IntToStringConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // guard type
        if(value is not int integerVal) { throw new ArgumentException("Can only convert from integer value"); }
        return integerVal.ToString();
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        // guard type
        if (value is not string stringVal) { throw new ArgumentException("Can only convert from string value"); }

        // try parsing to int
        int parsedVal;
        if(int.TryParse(stringVal, out parsedVal) == false)
        {
            // error
            parsedVal = -1;
        }
        return parsedVal;
    }
}