提交单例模式释放错误

DHSoftware/LoginWindow.cs

@@ -25,7 +25,7 @@ namespace DHSoftware
         {
             get
             {
-                if (_instance == null)
+                if (_instance == null || _instance.IsDisposed)
                     _instance = new LoginWindow();
                 return _instance;
             }

DHSoftware/Views/SettingWindow.cs

@@ -27,7 +27,7 @@ namespace DHSoftware.Views
         {
             get
             {
-                if (_instance == null)
+                if (_instance == null || _instance.IsDisposed)
                     _instance = new SettingWindow();
                 return _instance;
             }