C# Handle file errors

Question

I am trying to open a file, and I would like to return eg X if the filepath does not exist, Y if the file can't be opened, and Z if it was successful.

However, I can't understand how I can check for the "file can't be opened" error and I am not sure my try-catch is correct so far. I would also like to add another statement to check if the file is already open.

public int Opener(string fileName)
    { 
    string text = "";
        
        try
        {
            text = File.ReadAllText(fileName);
            return "Something to Return";
        }
        catch (FileNotFoundException)
        {
            return "Something to Return";
        }

Answer 1

You can use this to check the cases you described:

try
{
    string text = File.ReadAllText(fileName);

    //Z: reading was successful
}
catch (Exception ex)
{
    if (ex.InnerException is IOException)
    {
        //Y: file is already being read
    }
    else if (ex.InnerException is FileNotFoundException)
    {
        //X: file does not exist
    }
}

Answer 2

The function is declared to return an int , so you need a number there, like -1, 0, or 1. If you want to return a text error message, change the function return type to string .