ComPDFKit.Tool(win) - 处理创建注释时指针可能为空的情况

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

@@ -24,6 +24,9 @@ namespace ComPDFKit.Tool
 
         public void CreateDefaultAnnot(CPDFAnnotation cPDFAnnotation, C_ANNOTATION_TYPE annotType, AnnotParam annotParam)
         {
+            if (cPDFAnnotation == null || !cPDFAnnotation.IsValid())
+                return;
+
             switch (annotType)
             {
                 case C_ANNOTATION_TYPE.C_ANNOTATION_NONE: