Question

I am creating an xml file. I need to check first if the file exists or not. If the file does not exist, create it and add the data cmg from a .cs file.

If the file exists, don’t create the file just add the data cmg from a .cs file.

My code looks like this:

string filename="c:\\employee.xml";
XmlTextWriter tw=new XmlTextWriter(filename,null);//null represents 
the Encoding Type//
tw.Formatting=Formatting.Indented; //for xml tags to be indented//
tw.WriteStartDocument(); //Indicates the starting of document (Required)//
tw.WriteStartElement("Employees"); 
tw.WriteStartElement("Employee","Genius");
tw.WriteStartElement("EmpID","1");
tw.WriteAttributeString("Name","krishnan");
tw.WriteElementString("Designation","Software Developer");
tw.WriteElementString("FullName","krishnan Lakshmipuram Narayanan");
tw.WriteEndElement();
tw.WriteEndElement();
tw.WriteEndDocument(); 
tw.Flush();
tw.Close();

• so next time we add data to file we need to check if the file exits and add data to xml file
• and as we have made empID as a primary key, if user tries to make duplicate entry we need to avoid

Is this possible to do?

Answer 1

if (!File.Exists(filename))
{
    // create your file
}

or

if (File.Exists(filename))
{
    File.Delete(filename);
}

// then create your file

File class is in System.IO namespace (add using System.IO; to your file)