ComPDFKit.Tool(Win) - 修复文件对比Tools层错误

Demo/Examples/ComPDFKit.Tool/CPDFViewerTool.PDFCompareEffect.cs

@@ -33,7 +33,7 @@ namespace ComPDFKit.Tool
             int maxId = PDFViewer.GetMaxViewIndex();
             CustomizeLayer customizeLayer = new CustomizeLayer();
             PDFViewer.InsertView(maxId, customizeLayer);
-            PDFCompareViewID = maxId;
+            PDFCompareViewID = customizeLayer.GetResTag();
             PDFViewer.DrawChanged -= DrawChangedNotify;
             PDFViewer.DrawChanged += DrawChangedNotify;
             return customizeLayer;
@@ -41,6 +41,10 @@ namespace ComPDFKit.Tool
 
         private void DrawPDFCompare()
         {
+            if (PDFCompareViewID==-1)
+            {
+                return;
+            }
             CustomizeLayer drawLayer = GetPDFCompareDrawView();
             if (drawLayer == null)
             {
@@ -107,7 +111,10 @@ namespace ComPDFKit.Tool
             PDFComparePageIndex = PageIndex;
             PDFCompareBrush = FillBrush;
             PDFComparePen = BorderPen;
-
+            if(PDFCompareViewID==-1)
+            {
+                GetPDFCompareDrawView();
+            }
             DrawPDFCompare();
         }