佛山工厂量产随机快速复制

Signed-off-by: TRADER_FOER <lhf190@outlook.com>

Assets/Scripts/CommandSystem/CommandGroup.cs

@@ -8,9 +8,11 @@ namespace Ichni.Editor.Commands
     public class CommandGroup : ICommand
     {
         private List<ICommand> commands = new List<ICommand>();
+        public int Count => commands.Count;
 
         public void Add(ICommand cmd)
         {
+            if (cmd == null) return;
             commands.Add(cmd);
         }