fixed #259

src/Shared/HandyControl_Shared/Tools/Converter/Color2HexStrConverter.cs

@@ -30,11 +30,11 @@ namespace HandyControl.Tools.Converter
                 }
                 catch
                 {
-                    return new SolidColorBrush(default(Color));
+                    return new SolidColorBrush(default);
                 }
-                return new SolidColorBrush(default(Color));
+                return new SolidColorBrush(default);
             }
-            return new SolidColorBrush(default(Color));
+            return new SolidColorBrush(default);
         }
     }
 }

src/Shared/HandyControl_Shared/Tools/Converter/DoubleMinConverter.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+using HandyControl.Tools.Extension;
+
+namespace HandyControl.Tools.Converter
+{
+    public class DoubleMinConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is double doubleValue)
+            {
+                if (parameter is string str)
+                {
+                    var minValue = str.Value<double>();
+                    return doubleValue < minValue ? minValue : doubleValue;
+                }
+
+                return doubleValue < .0 ? .0 : doubleValue;
+            }
+
+            return .0;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}