【预览】向前/向后功能置灰了，不可用

PDF Office/PDF Master/Class/PDFWindowController/ViewController/KMMainViewController.swift

@@ -202,6 +202,9 @@ import Cocoa
     
     override func viewDidAppear() {
         super.viewDidAppear()
+        //刷新向前向后按钮
+        self.updateBackAndForwardButtonState()
+        
         KMLightMemberManager.manager.canShowAdvancedView = false
         Task { @MainActor in
             await KMLightMemberManager.manager.canUseAdvanced(needNetworking: true)
@@ -347,8 +350,6 @@ import Cocoa
 
         self.addKeyEventMonitor()
         
-        //刷新状态
-        self.updateBackAndForwardButtonState()
     }
         
     //MARK: - PDFListView
@@ -1395,12 +1396,16 @@ import Cocoa
         if self.isReadMode {
             self.readModelView.currentPageIndex = self.listView.currentPageIndex
         }
+        //刷新向前向后按钮
+        self.updateBackAndForwardButtonState()
     }
     
     func CPDFDocumentPageCountChangedNotification(_ sender: Notification) {
         if self.isReadMode {
             self.readModelView.totalPagesCount = Int(self.listView.document.pageCount)
         }
+        //刷新向前向后按钮
+        self.updateBackAndForwardButtonState()
     }
     
     func CEditPDFToolModeChangeStateUnkownNotification(_ sender: Notification) {