A simple disk-to-screen utility that demonstrates a FileReader

image_pdfimage_print


   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

/* A simple disk-to-screen utility that 
   demonstrates a FileReader. */ 
 
using System; 
using System.IO;  
 
public class DtoS { 
  public static void Main() { 
    FileStream fin; 
    string s; 
 
    try { 
      fin = new FileStream("test.txt", FileMode.Open); 
    } 
    catch(FileNotFoundException exc) { 
      Console.WriteLine(exc.Message + "Cannot open file."); 
      return ; 
    }  
 
    StreamReader fstr_in = new StreamReader(fin); 
 
    // Read the file line-by-line. 
    while((s = fstr_in.ReadLine()) != null) { 
      Console.WriteLine(s); 
    } 
 
    fstr_in.Close(); 
  } 
}


           
          


illustrates use of FileStreams 2

image_pdfimage_print


   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

 /*
  Example15_11.cs illustrates use of FileStreams
*/

using System;
using System.Windows.Forms;
using System.IO;

public class Example15_11 
{
    [STAThread]
  public static void Main() 
  {

    // use an open file dialog to get a filename
    OpenFileDialog dlgOpen = new OpenFileDialog();
    dlgOpen.Title="Select file to back up";

    if (dlgOpen.ShowDialog() == DialogResult.OK)
    {
      FileStream inStream = File.OpenRead(dlgOpen.FileName);
      FileStream outStream = 
        File.OpenWrite(dlgOpen.FileName + ".bak");
      byte[] buf = new byte[4096];
      int bytesRead;

      // copy all data from in to out
      while ((bytesRead = inStream.Read(buf, 0, 4096)) > 0)
        outStream.Write(buf, 0, bytesRead);

      // clean up
      outStream.Flush();
      outStream.Close();
      inStream.Close();

    }

  }

}



           
          


illustrates use of FileStreams

image_pdfimage_print


   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

 /*
  Example15_10.cs illustrates use of FileStreams
*/

using System;
using System.Windows.Forms;
using System.IO;

public class Example15_10 
{
    [STAThread]
  public static void Main() 
  {

    // use an open file dialog to get a filename
    OpenFileDialog dlgOpen = new OpenFileDialog();
    dlgOpen.Title="Select file to back up";

    if (dlgOpen.ShowDialog() == DialogResult.OK)
    {
      FileStream inStream = File.OpenRead(dlgOpen.FileName);
      FileStream outStream = 
       File.OpenWrite(dlgOpen.FileName + ".bak");
      int b;

      // copy all data from in to out
      while ((b = inStream.ReadByte()) > -1)
        outStream.WriteByte( (byte) b);

      // clean up
      outStream.Flush();
      outStream.Close();
      inStream.Close();

    }

  }

}



           
          


illustrates reading and writing binary data

image_pdfimage_print


   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/


 /*
  Example15_15.cs illustrates reading and writing binary data
*/

using System;
using System.IO;

public class Example15_15 
{

  public static void Main() 
  {

    // create a new file to work with
    FileStream outStream = File.Create("c:BinaryTest.dat");

    // use a BinaryWriter to write formatted data to the file
    BinaryWriter bw = new BinaryWriter(outStream);

    // write various data to the file
    bw.Write( (int) 32);
    bw.Write( (decimal) 4.567);
    string s = "Test String";
    bw.Write(s);

    // flush and close
    bw.Flush();
    bw.Close();

    // now open the file for reading
    FileStream inStream = File.OpenRead("c:BinaryTest.dat");

    // use a BinaryReader to read formatted data and dump it to the screen
    BinaryReader br = new BinaryReader(inStream);

    int i = br.ReadInt32();
    decimal d = br.ReadDecimal();
    string s2 = br.ReadString();

    Console.WriteLine(i);
    Console.WriteLine(d);
    Console.WriteLine(s2);

    // clean up
    br.Close();

  }

}


           
          


Create StreamReader from File Stream

image_pdfimage_print
   


using System;
using System.IO;

public class IOExample
{
  static void Main() {   
    FileStream fs;
    StreamReader srIn;

    try {
      fs = new FileStream("practice.txt", FileMode.Open );
      srIn = new StreamReader(fs);

      string line = srIn.ReadLine();

      Console.WriteLine("line = "+line);
      srIn.Close();
    } catch (IOException ioe) {
      Console.WriteLine("IOException occurred: "+ioe.Message);
    }
  }
}

           
          


Reads lines separated by vertical bars

image_pdfimage_print


   

using System;
using System.IO;

public class FileReadAddresses {
  public static void Main( ) {
    String line;
    String street, city, state, zip;
    StreamReader f = new StreamReader("test.data");
    while ((line=f.ReadLine())!= null){
      String[] strings = line.Split(new char[]{'|'});
      if (strings.Length == 4) {
        street = strings[0];
        city = strings[1];
        state = strings[2];
        zip = strings[3];
        Console.WriteLine(street); 
        Console.WriteLine(city);
        Console.WriteLine(state);
        Console.WriteLine(zip);
      }
    }
    f.Close();
  }
}    

//File: test.data
/*
4665 Street|Toronto|ON|90048
*/