添加项目文件。

Sai.Toolkit.Mvvm/Converters/StringsIsNotNullOrEmptyCheck.cs

@@ -0,0 +1,26 @@
+using System.Globalization;
+using System.Windows.Data;
+
+namespace Sai.Toolkit.Mvvm.Converters;
+
+public class StringsIsNotNullOrEmptyCheck : IMultiValueConverter
+{
+	public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
+	{
+		foreach (var item in values)
+		{
+			string s = item.ToString();
+			if (string.IsNullOrWhiteSpace(s))
+			{
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
+	{
+		throw new NotImplementedException();
+	}
+}