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  1. #1
    Join Date
    Dec 2011
    Posts
    1

    Beginner problems - reading / writing to a file

    Hey, new here, and pretty much new to c#.. Only programming I've done before was Pascal in 6th form, and that was horrendous, but fairly easy.

    Anyways, I'm trying to learn c# (it's a module for the course I'm on) by programming things outside of the course.

    We haven't got to this section yet, but I need it for the program I'm making..

    So anyway, how would I read / write variables to a file, so I can use them later?

    Essentially it's a addition program, which counts how much I smoke a day, but obviously I'm gonna have to close the program at some point, thus losing the data I'd put in.

    Any ideas? (Sorry if this is a ridiculously basic question).

    Oh, and I'm using Visual Studio 2010 (Net 4.0 I believe).

    Thanks in advance.

  2. #2
    Join Date
    Feb 2011
    Location
    United States
    Posts
    1,016

    Re: Beginner problems - reading / writing to a file

    The complicated way is with objects and serialization: http://www.switchonthecode.com/tutor...ects-to-a-file

    The simple way is to do something like this:

    Code:
    string someString;
    int someInteger;
    
    public void saveData(string savePath)
    {
        StreamWriter w = new StreamWriter(savePath);
        
        w.WriteLine(someString);    //Write the string
        w.WriteLine(someInteger);   //Write the integer
        
        w.Close();
    
    }
    Suppose somestring had text "this is a string!" and someInteger = 5 then this produces a file
    with contents

    Code:
    this is a string!
    5
    You can read the data back in with a method that looks like this:

    Code:
    public void loadData(string loadPath)
    {
        StreamReader r = new StreamReader(loadPath);
        
        //Read in the string
        someString = r.ReadLine();
        
        //Read in the integer (as a string) and then parse it to int
        someInteger = Int32.Parse(r.ReadLine());
        
        r.Close();
    }
    If you have other (primitive) types: say you want to save a double, use Double.Parse(double), or for bool, use bool.Parse(bool), etc...

    Also make sure you add using System.IO to the top of your file (which is the namespace in which StreamReader and StreamWriter live).

    Does that make sense? Let me know if you have more questions.
    Best Regards,

    BioPhysEngr
    http://blog.biophysengr.net
    --
    All advice is offered in good faith only. You are ultimately responsible for effects of your programs and the integrity of the machines they run on.

  3. #3
    Join Date
    Oct 2003
    Location
    .NET2.0 / VS2005 Developer
    Posts
    7,104

    Re: Beginner problems - reading / writing to a file

    Actually, the easy way is to use settings:
    http://msdn.microsoft.com/en-us/libr...(v=vs.80).aspx
    "it's a fax from your dog, Mr Dansworth. It looks like your cat" - Gary Larson...DW1: Data Walkthroughs 1.1...DW2: Data Walkthroughs 2.0...DDS: The DataSet Designer Surface...ANO: ADO.NET2 Orientation...DAN: Deeper ADO.NET...DNU...PQ

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