update MeasureFile.cs

MeasureData/MeasureFile.cs

@@ -215,14 +215,14 @@ namespace MeasureData
 
                 //创建一个新的文件
                 XmlDocument doc = new XmlDocument();
-                if (!Directory.Exists(this.FilePath))
+                if (!File.Exists(this.FileName))
                 {
                     if (CreateXml() > 0)//创建该文件？
                     {
                         return false;
                     }
                 }
-
+                doc.Load(this.FileName);
                 XmlNode root = doc.SelectSingleNode("XMLData");
                 Serialize(true, doc, root);
                 doc.Save(this.FileName);