--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MetroWpf/MetroWpf.Xaml/Converters/IsStringNullOrWhitespaceConverter.cs	Mon Mar 12 23:05:21 2012 +0800
@@ -0,0 +1,37 @@
+
+namespace MetroWpf.Xaml.Converters
+{
+    using System;
+    using System.Windows.Data;
+    using System.Globalization;
+
+    public class IsStringNullOrWhitespaceConverter : IValueConverter
+    {
+        #region IValueConverter Members
+
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            var str = (string)value;
+            bool ret = string.IsNullOrEmpty(str);
+            if (!ret)
+            {
+                str = str.Trim();
+                ret = string.IsNullOrEmpty(str);
+            }
+
+            if ((string)parameter == "Inverse")
+            {
+                ret = !ret;
+            }
+
+            return ret;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotSupportedException();
+        }
+
+        #endregion
+    }
+}