/// <summary>
/// Open an existing text file for reading
/// </summary>
/// <param name="filePath">
/// The file path and file name of the text file to be opened
/// </param>
public virtual void OpenForRead(string filePath)
{
// Check to see if the file is already open. Throw an exception if it is.
if (State == FileState.OPEN)
{
throw new FileOpenException("File already open")
{
FilePath = DirectoryPath,
FileName = FileName
};
}
// Obtain the absolute file path. Throw an exception if the path is invalid.
ParseFilePath(filePath);
// Throw an exception if the file doesn't exist.
FileOps.FileMustExist(FilePath);
State = FileState.OPEN;
Mode = FileMode.READ;
// Read the contents of the file into the _fileData collection
try
{
using (StreamReader sr = new StreamReader(FilePath))
{
while (sr.Peek() >= 0) // Check to see if we've reached the end of the file
{
_fileData.Add(sr.ReadLine()); // Read the next line from the file
}
if (Count > 0)
{
Position = 0; // Set the position index to the first line
}
else
{
Position = -1; // Set position index to a negative number if the file is empty
}
}
}
catch (Exception e)
{
string msg = $"Error reading line {Count + 1} from file";
throw new FileIOException(msg, e)
{
FilePath = DirectoryPath,
FileName = FileName
};
}
}
/// <summary>
/// Open an existing text file for writing
/// </summary>
/// <param name="filePath">
/// The file path and file name of the text file to be opened
/// </param>
public virtual void OpenForWrite(string filePath)
{
// Check to see if the file is already open. Throw an exception if it is.
if (State == FileState.OPEN)
{
throw new FileOpenException("File already open")
{
FilePath = DirectoryPath,
FileName = FileName
};
}
// Obtain the absolute file path.
ParseFilePath(filePath);
// Throw an exception if the file doesn't exist.
FileOps.FileMustExist(FilePath);
// Finish opening the text file for writing
State = FileState.OPEN;
Mode = FileMode.WRITE;
Position = 0;
}