hc:CheckComboBox support for Validation

src/Net_40/HandyControl_Net_40/Themes/Styles/Base/CheckComboBoxBaseStyle.xaml

@@ -172,6 +172,7 @@
         <Setter Property="Padding" Value="{StaticResource DefaultInputPadding}"/>
         <Setter Property="Template" Value="{StaticResource CheckComboBoxTemplate}"/>
         <Setter Property="VerticalContentAlignment" Value="Center"/>
+        <Setter Property="Validation.ErrorTemplate" Value="{x:Null}"/>
     </Style>
 
     <ControlTemplate x:Key="CheckComboBoxExtendTopTemplate" TargetType="hc:CheckComboBox">
@@ -534,6 +535,7 @@
     </ControlTemplate>
 
     <Style x:Key="CheckComboBoxPlusBaseStyle" BasedOn="{StaticResource CheckComboBoxExtendBaseStyle}" TargetType="hc:CheckComboBox">
+        <Setter Property="IsError" Value="{Binding Path=(Validation.HasError),RelativeSource={RelativeSource Self}}"/>
         <Setter Property="Template" Value="{StaticResource CheckComboBoxPlusTopTemplate}"/>
         <Style.Triggers>
             <Trigger Property="hc:InfoElement.TitlePlacement" Value="Left">

src/Shared/HandyControl_Shared/Controls/Input/CheckComboBox/CheckComboBox.cs

@@ -185,9 +185,22 @@ namespace HandyControl.Controls
                 }
             }
 
-            IsError = !result.Data;
-            ErrorStr = result.Message;
-            return result.Data;
+            var isError = !result.Data;
+            if (isError)
+            {
+                SetCurrentValue(IsErrorProperty, true);
+                SetCurrentValue(ErrorStrProperty, result.Message);
+            }
+            else
+            {
+                isError = Validation.GetHasError(this);
+                if (isError)
+                {
+                    SetCurrentValue(ErrorStrProperty, Validation.GetErrors(this)[0].ErrorContent);
+                }
+            }
+
+            return !isError;
         }
 
         public Func<string, OperationResult<bool>> VerifyFunc { get; set; }

src/Shared/HandyControl_Shared/Themes/Styles/Base/CheckComboBoxBaseStyle.xaml

@@ -179,6 +179,7 @@
         <Setter Property="Padding" Value="{StaticResource DefaultInputPadding}"/>
         <Setter Property="Template" Value="{StaticResource CheckComboBoxTemplate}"/>
         <Setter Property="VerticalContentAlignment" Value="Center"/>
+        <Setter Property="Validation.ErrorTemplate" Value="{x:Null}"/>
     </Style>
 
     <ControlTemplate x:Key="CheckComboBoxExtendTopTemplate" TargetType="hc:CheckComboBox">
@@ -569,6 +570,7 @@
     </ControlTemplate>
 
     <Style x:Key="CheckComboBoxPlusBaseStyle" BasedOn="{StaticResource CheckComboBoxExtendBaseStyle}" TargetType="hc:CheckComboBox">
+        <Setter Property="IsError" Value="{Binding Path=(Validation.HasError),RelativeSource={RelativeSource Self}}"/>
         <Setter Property="Template" Value="{StaticResource CheckComboBoxPlusTopTemplate}"/>
         <Style.Triggers>
             <Trigger Property="hc:InfoElement.TitlePlacement" Value="Left">