Manually writing to and reading from files

Apart from the built-in object types for creating text files and XML files, you can also create them manually. This recipe will show you how to write your own code to do this.

How to do it...

1. Create a new codeunit from Object Designer.

2. Add the following global variables:

   Name	DataType
   StreamOut	OutStream
   FileOut	File
   StreamIn	InStream
   FileIn	File

3. Add the following code to the OnRun trigger:

   IF NOT FileOut.CREATE('C:\NAVFile.txt') THEN
   IF NOT FileOut.OPEN('C:\NAVFile.txt') THEN
   ERROR('Unable to write to file!');
   FileOut.CREATEOUTSTREAM(StreamOut);
   StreamOut.WRITETEXT('Line 1');
   StreamOut.WRITETEXT();
   StreamOut.WRITETEXT('Line 2');
   StreamOut.WRITETEXT();
   FileOut.CLOSE;
   IF NOT FileIn.OPEN('C:\NAVFile.txt') THEN
   ERROR('Unable to read file!');
   FileIn.CREATEINSTREAM(StreamIn);
   WHILE NOT StreamIn.EOS DO BEGIN
   StreamIn.READTEXT(TextLine);
   MESSAGE('%1', TextLine);
   END;
   FileIn.CLOSE;
   

4. Save and close the codeunit.

How it works...

First we try to create a...