添加项目文件。

Sai.RvKits/RvView/SwitchBackgroundCmd.cs

@@ -0,0 +1,18 @@
+using Autodesk.Revit.DB;
+
+using Nice3point.Revit.Toolkit.External;
+
+using UIFramework;
+
+namespace Sai.RvKits.RvView;
+
+[Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Manual)]
+[Autodesk.Revit.Attributes.Regeneration(Autodesk.Revit.Attributes.RegenerationOption.Manual)]
+public class SwitchBackgroundCmd : ExternalCommand
+{
+    public override void Execute()
+    {
+        var col = Application.BackgroundColor;
+        Application.BackgroundColor = col.Red == 255 && col.Green == 255 && col.Blue == 255 ? new Color(32, 40, 49) : new Color(255, 255, 255);
+    }
+}