using System.Configuration.Internal; using System.Xml; namespace System.Configuration { internal sealed class PropertySourceInfo { internal string FileName { get; } internal int LineNumber { get; } internal PropertySourceInfo(XmlReader reader) { FileName = GetFilename(reader); LineNumber = GetLineNumber(reader); } private string GetFilename(XmlReader reader) { IConfigErrorInfo configErrorInfo = reader as IConfigErrorInfo; if (configErrorInfo == null) return ""; return configErrorInfo.Filename; } private int GetLineNumber(XmlReader reader) { return (reader as IConfigErrorInfo)?.LineNumber ?? 0; } } }