Convert Text.txt file .xml format

Question

I try to convert text file to xml file using following code. But i get error in line 12. Could any one correct it and give me the correct answer.

private void button1_Click(object sender, EventArgs e)
{

    string[] lines = File.ReadAllLines("ex3.txt");
    char[] ca = new char[] { '~' };
    using (XmlTextWriter writer = new XmlTextWriter("ex3.xml", null))
    {
        writer.Formatting = Formatting.Indented;
        writer.WriteStartDocument();
        writer.WriteStartElement("Root");
        writer.WriteStartElement("Header");
        writer.WriteStartElement("H1");
        writer.WriteString(lines[0].TrimEnd().Split(ca, 2)[1]);
        writer.WriteEndElement();
        writer.WriteStartElement("H2");
        writer.WriteString(lines[1].TrimEnd().Split(ca, 2)[1]);
        writer.WriteEndElement();
        writer.WriteEndElement();
        writer.WriteStartElement("Details");
        for (int i = 2; i < lines.Length - 2; i++)
        {
            writer.WriteStartElement("D" + (i - 1).ToString());
            writer.WriteString(lines[i].TrimEnd().Split(ca, 2)[1]);
            writer.WriteEndElement();
        }
        writer.WriteEndElement();
        writer.WriteStartElement("Footer");
        writer.WriteStartElement("F1");
        writer.WriteString(lines[lines.Length - 2].TrimEnd().Split(ca, 2)[1]);
        writer.WriteEndElement();
        writer.WriteStartElement("F2");
        writer.WriteString(lines[lines.Length - 1].TrimEnd().Split(ca, 2)[1]);
        writer.WriteEndElement();
        writer.WriteEndElement();
        writer.WriteEndDocument();
    }
}

Thanks

This is the Error

System.IndexOutOfRangeException was unhandled Message="Index was outside the bounds of the array." Source="txtxml" StackTrace: at txtxml.Form1.button1_Click(Object sender, EventArgs e) in C:\Documents and Settings\Crusaders\My Documents\Visual Studio 2005\Projects\txtxml\txtxml\Form1.cs:line 31 at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(Form mainForm) at txtxml.Program.Main() in C:\Documents and Settings\Crusaders\My Documents\Visual Studio 2005\Projects\txtxml\txtxml\Program.cs:line 17 at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()

How does the text file look like? How does the resulting XML file should look like? Give examples of both before expecting any meaningful answers. Also providing the exact error message you are getting might be helpful. — Darin Dimitrov
I bet 2 cents that the error is IndexOutOfRangeException :-) — Darin Dimitrov
@Kasun, providing the error message is the first step towards getting help. The next step is providing an example of the input text file and the expected output XML file. — Darin Dimitrov
So what is your function supposed to do? If you are not capable of explaining what is the expected output of your function for a given sample input, believe me, you will NEVER succeed in writing a working function. — Darin Dimitrov

LBushkin LBushkin · Accepted Answer · 2010-06-07T18:30:16

The code assumes that there exist at least four lines of text in the file. Are you sure this is the case?

I would suggest you write your code to first assert that the lines array actually contains as many lines as you expect. It's entirely possible that the file does not - or that the line breaks are non-standard and therefore not recognized by ReadAllLines().

string[] lines = File.ReadAllLines("ex3.txt"); 
char[] ca = new char[] { '~' }; 
if( lines.Length < 4 ) { /* decide how to handle this... */ }

//... your code

As a general rule, when parsing or splitting the contents of a file that you expect to have a certain format, you should write your code in a way that asserts your expectations. Otherwise, it can become quite difficult to diagnose what occurred when things go wrong.

Another place in your code you may want to re-examine, are lines like:

writer.WriteString(lines[0].TrimEnd().Split(ca, 2)[1]);

Here, again, you assume that the line has a certain structure, and then you access the second index in the result using the indexing operator [] - which could also be a potential source of the error.

Convert Text.txt file .xml format

2 Answers