Question

When trying to replace the content of an XML file in C#.NET with a snippet like this:

string file = Path.GetTempFileName(); // pretend this is a real file string tmpFile = Path.GetTempFileName();  using (var writer = XmlWriter.Create(File.Create(tmpFile))) {     writer.WriteStartElement('root');     for (int i = 0; i < 100; i++)     {         writer.WriteElementString('test', null,              'All work and no play makes Jack a dull boy');     }     writer.WriteEndElement(); }  File.Delete(file); File.Move(tmpFile, file); 

… I get a System.IO.IOException claiming that the file is already opened by another process.

Answer 1

For some reason the XmlWriter class evidently does not dispose the underlying stream for the temporary file. Putting the stream in a ‘using’ clause of its own makes sure the stream is closed correctly. Changing the code to

string file = Path.GetTempFileName(); // pretend this is a real file string tmpFile = Path.GetTempFileName();  using (var stream = File.Create(tmpFile)) using (var writer = XmlWriter.Create(stream)) {     writer.WriteStartElement('root');     for (int i = 0; i < 100; i++)     {         writer.WriteElementString('test', null,              'All work and no play makes Jack a dull boy');     }     writer.WriteEndElement(); }                 File.Delete(file); File.Move(tmpFile,file); 

… makes the IOException disappear and it works as intended.