c#获取和新增带命名空间的xml节点

    XmlDocument xmlDoc = new XmlDocument();  
      
        xmlDoc.Load("指定xml文件地址以及文件名");  
      
        XmlNode root = xmlDoc.DocumentElement;  
          
        XmlNamespaceManager nsp = new XmlNamespaceManager(xmlDoc.NameTable);  
        nsp.AddNamespace("my", "http://schemas.microsoft.com/office/infopath/2003/myXSD/2012-05-15T08:53:20");  
    	//获取指定节点  
         a = root.SelectSingleNode("my:ANLToDate",nsp).InnerText;  
         string ToTime = root.SelectSingleNode("my:ANLTime", nsp).InnerText;  
          
         a = a + "T" + ToTime + ":00";  
    //新增一个<my:Ca