【幻灯片】幻灯片undo方法问题优化

PDF Office/PDF Master/Class/PDFWindowController/MainWindowController/KMPresentationTopViewController.swift

@@ -190,7 +190,7 @@ public class KMPresentationTopViewController: NSViewController, KMDrawViewDelega
     }
     
     public func drawView(_ drawView: KMDrawView!, didDrawEnd point: CGPoint) {
-        
+        undoButton.isEnabled = ((pdfView?.presentationDrawView.canUndo()) == true)
     }
 
 }