添加项目文件。

Sai.Toolkit.Mvvm/Converters/Null2EnableConverter.cs

@@ -0,0 +1,20 @@
+using System.Globalization;
+using System.Windows.Data;
+
+namespace Sai.Toolkit.Mvvm.Converters;
+
+/// <summary>
+///     未选择或选择为空时，不可用
+/// </summary>
+public class Null2EnableConverter : IValueConverter
+{
+	public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+	{
+		return (int)value != -1;
+	}
+
+	public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+	{
+		throw new NotImplementedException();
+	}
+}