merged pr

src/Core_30/HandyControlDemo_Core_30/HandyControlDemo_Core30.csproj

@@ -23,6 +23,7 @@
     <PackageReference Include="CommonServiceLocator" Version="2.0.2" />
     <PackageReference Include="MvvmLightLibs" Version="5.4.1.1" />
     <PackageReference Include="Newtonsoft.Json" Version="11.0.2" />
+    <PackageReference Include="System.Management" Version="4.6.0-preview7.19362.9" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\..\Shared\HandyControlDemo_Shared\Data\MessageToken.cs">

src/Core_30/HandyControl_Core_30/HandyControl_Core_30.csproj

@@ -45,9 +45,6 @@
   <ItemGroup>
     <None Remove="Themes\Styles\Base\TreeViewBaseStyle.xaml" />
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="System.Management" Version="4.6.0-preview7.19362.9" />
-  </ItemGroup>
   <ItemGroup>
     <Resource Include="..\..\Shared\HandyControl_Shared\Resources\dropper.cur">
       <Link>Resources\dropper.cur</Link>

src/Net_40/HandyControlDemo_Net_40/HandyControlDemo_Net_40.csproj

@@ -57,7 +57,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="MvvmLightLibs">
-      <Version>5.4.1</Version>
+      <Version>5.4.1.1</Version>
     </PackageReference>
     <PackageReference Include="Newtonsoft.Json">
       <Version>11.0.2</Version>

src/Net_GE45/HandyControlDemo_Net_GE45/HandyControlDemo_Net_GE45.csproj

@@ -127,7 +127,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="MvvmLightLibs">
-      <Version>5.4.1</Version>
+      <Version>5.4.1.1</Version>
     </PackageReference>
     <PackageReference Include="Newtonsoft.Json">
       <Version>11.0.2</Version>

src/Shared/HandyControlDemo_Shared/Tools/Helper/CommonHelper.cs

@@ -19,7 +19,7 @@ namespace HandyControlDemo.Tools
                     return info;
                 }
             }
-            return default(SystemVersionInfo);
+            return default;
         }
     }
 }