ComPDFKit.Demo(win) - 修复使用签名注释面板添加注释崩溃的问题

Demo/Examples/Compdfkit.Controls/Annotation/PDFAnnotationPanel/PDFAnnotationUI/CPDFSignatureUI.xaml.cs

@@ -75,8 +75,8 @@ namespace ComPDFKit.Controls.Annotation.PDFAnnotationPanel.PDFAnnotationUI
             else
             {
                 FillForm(((sender as ListBoxItem).DataContext as CPDFSignatureData).SourcePath);
+                viewControl.PDFViewTool.IsDocumentModified = true;
             }
-            viewControl.PDFViewTool.IsDocumentModified = true;
         }
 
         private void FillForm(string imagePath)