Question

Following code, credit: Guffa.

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Hello All,

I’m trying to add controls to a Form at runtime based on the information found in a Plain Text File. The structure? of the text file is always the same, and will not change. Example:

File.txt:

Label
"This is a label"
320, 240

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Explanation:

Control
Text
Location

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The following code, provided to me by Guffa, doesn’t cause any errors or anything, but at the same time, nothing happens at all. And I’m not sure why… Can somebody please explain why the label doesn’t get created and added to the form with the right info attached to it?

MatchCollection lines = Regex.Matches(File.ReadAllText(fileName), @"(.+?)\r\n""([^""]+)""\r\n(\d+), (\d+)\r\n");
foreach (Match match in lines) {
   string control = match.Groups[1].Value;
   string text = match.Groups[2].Value;
   int x = Int32.Parse(match.Groups[3].Value);
   int y = Int32.Parse(match.Groups[4].Value);
   Console.WriteLine("{0}, \"{1}\", {2}, {3}", control, text, x, y);

   if(control == "Label")
   {
      Label label = new Label();
      label.Text = text;
      canvas.Controls.Add(label); // canvas is a Panel Control.
      label.Location = new Point(x, y);
   }

}

I hope that I have clearly explained my situation. Any help at all would be greatly appreciated.

Thanks for taking the time to read.
jase

Answer 1

Blind guess: I see the last \r\n in the regex is not optional. Possible that your input file is missing a return character after the last line?

Additional note about sucking at regular expressions: there are some tools that will help you experiment with regular expressions, which might be useful, for example, to understand what’s going on in this particular case. I always use Expresso, which among other things analyzes the structure of the regular expression you provide and explains what it does.