添加项目文件。

MainModule/ViewModels/MainViewModel.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Linq;
+using System.Windows;
+using System.Windows.Input;
+using UIShare.PubEvent;
+using MainModule.ViewModels;
+using UIShare.ViewModelBase;
+
+
+namespace MainModule.ViewModels
+{
+    public class MainViewModel : NavigateViewModelBase, IRegionMemberLifetime
+    {
+        #region 私有字段
+        private bool IsInitialized = false;
+        private string _expandedCellName = string.Empty;
+        #endregion
+        
+        #region 属性
+        public bool KeepAlive => true; // 保持存活
+        
+        public string ExpandedCellName
+        {
+            get => _expandedCellName;
+            set => SetProperty(ref _expandedCellName, value);
+        }
+        #endregion
+        
+        #region 命令
+        public ICommand LoadedCommand { get; set; }
+        #endregion
+        
+        public MainViewModel(IContainerProvider containerProvider) : base(containerProvider)
+        {
+            LoadedCommand = new DelegateCommand(OnLoaded);
+            _eventAggregator.GetEvent<ExpandViewEvent>().Subscribe(OnCellExpandRequested);
+        }
+        
+        #region 命令处理与事件
+        private void OnLoaded()
+        {
+            if (IsInitialized) return;
+            for (int i = 1; i <= 9; i++)
+            {
+                var parameters = new NavigationParameters { { "Name", $"TestCell{i}" } };
+                _regionManager.RequestNavigate($"TestCell{i}", "ProtocolStartView", parameters);
+            }
+            IsInitialized = true;
+        }
+        
+        // 不再物理搬迁视图，只需修改一个字符串属性 ExpandedCellName，
+        // XAML 里每个单元的 Style.Triggers 会根据该值处理隐藏 / 跨越 3x3。
+        private void OnCellExpandRequested(string cellName)
+        {
+            ExpandedCellName = cellName ?? string.Empty;
+        }
+        #endregion
+
+        #region 重写
+        public override bool IsNavigationTarget(NavigationContext navigationContext)
+        {
+            // 之前帮你改好的单例复用逻辑（防止重复 new 和初始化视图）
+            return true;
+        }
+        #endregion
+    }
+}