该进程无法访问'xml'文件，因为它正由另一个进程使用

Question

I want to update a file. I opened the file and then tried to write the content to it but got the exception:

The process cannot access the file because it is being used by another process.

XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;

XmlWriter writer = XmlWriter.Create("../../../connString.xml", settings);
writer.WriteStartDocument();
writer.WriteComment("This file is generated by the program.");
writer.WriteStartElement("ConnectionString");

if (ConnType == "SQL Server") {
   writer.WriteAttributeString("ID", "SQL Server");
   writer.WriteAttributeString("DataSource", Convert.ToString(TEServer.EditValue));
   writer.WriteAttributeString("Database", Convert.ToString(TEDatabase.EditValue));
   writer.WriteAttributeString("UserID", Convert.ToString(TEUserID.EditValue));
   writer.WriteAttributeString("Password", Convert.ToString(TEPassword.EditValue));
} else if (ConnType == "Access") {
   writer.WriteAttributeString("ID", "Access");
   writer.WriteAttributeString("DbLocation", Convert.ToString(BtnEditDBLoc.EditValue));
}

writer.WriteEndElement();
writer.WriteEndDocument();

writer.Flush();
writer.Close();

I've been looking at some sources said to be close "XmlWriter" but in my coding i have closed, with : writer.Close();

But still occurs the same error.

Is there anything that can help me, please?

Thanks.

Answer 1

Any of the writers (XmlWriter, FileWriter, etc.) should be wrapped in a using block so they are disposed of properly:

XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.CloseOutput = true; 

using (XmlWriter writer = XmlWriter.Create("../../../connString.xml", settings)) {
   writer.WriteStartDocument();
   writer.WriteComment("This file is generated by the program.");
   writer.WriteStartElement("ConnectionString");

   if (ConnType == "SQL Server") {
      writer.WriteAttributeString("ID", "SQL Server");
      writer.WriteAttributeString("DataSource", Convert.ToString(TEServer.EditValue));
      writer.WriteAttributeString("Database", Convert.ToString(TEDatabase.EditValue));
      writer.WriteAttributeString("UserID", Convert.ToString(TEUserID.EditValue));
      writer.WriteAttributeString("Password", Convert.ToString(TEPassword.EditValue));
   } else if (ConnType == "Access") {
      writer.WriteAttributeString("ID", "Access");
      writer.WriteAttributeString("DbLocation", Convert.ToString(BtnEditDBLoc.EditValue));
   }

   writer.WriteEndElement();
   writer.WriteEndDocument();

   //writer.Flush(); //Flush isn't required--handled by the using block
   //writer.Close(); //close isn't required--handled by the using block
}

I also added settings.CloseOutput = true; which may be necessary according to this SO answer

Answer 2

Use using block for accessing any file from system, as accessing any file create a process in our system, and so it neva allow same file to access by two thread . So, to close or exit tht process, alws use using block in C# , using block alws free the resources ur using in your project

Thank you