Disable DElButton when nothing to delete

Jugenddienst Stunden/Converter/IntBoolConverter.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Jugenddienst_Stunden.Converter;
+public class IntBoolConverter : IValueConverter {
+
+	public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture) {
+		if (value is int) {
+			return (int)value != 0;
+		}
+		return false;
+	}
+
+
+	public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) {
+		if (value is bool) {
+			return (bool)value ? 1 : 0;
+		}
+		return 0;
+	}
+}