add versioninfo in nonclientarea

src/Shared/HandyControlDemo_Shared/ViewModel/Main/NonClientAreaViewModel.cs

@@ -0,0 +1,39 @@
+using System;
+using GalaSoft.MvvmLight;
+using GalaSoft.MvvmLight.Command;
+using GalaSoft.MvvmLight.Messaging;
+using HandyControlDemo.Data;
+using HandyControlDemo.Tools;
+
+namespace HandyControlDemo.ViewModel
+{
+    public class NonClientAreaViewModel : ViewModelBase
+    {
+        public NonClientAreaViewModel()
+        {
+            VersionInfo = VersionHelper.GetVersion();
+        }
+
+        public RelayCommand<string> OpenViewCmd => new Lazy<RelayCommand<string>>(() =>
+            new RelayCommand<string>(OpenView)).Value;
+
+        private void OpenView(string viewName)
+        {
+            Messenger.Default.Send<object>(null, MessageToken.ClearLeftSelected);
+            Messenger.Default.Send(true, MessageToken.FullSwitch);
+            Messenger.Default.Send(AssemblyHelper.CreateInternalInstance($"UserControl.{viewName}"), MessageToken.LoadShowContent);
+        }
+
+        private string _versionInfo;
+
+        public string VersionInfo
+        {
+            get => _versionInfo;
+#if NET40
+            set => Set(nameof(VersionInfo), ref _versionInfo, value);
+#else
+            set => Set(ref _versionInfo, value);
+#endif
+        }
+    }
+}