в 15:31, 26 мая 2010

2010-05-26T15:31:19Z

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2010-05-26T11:45:33Z

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==An enhanced cipher component that maintains a log file==

<source lang="csharp">
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// An enhanced cipher component that maintains a log file.
using CipherLib; // import CipherComp"s namespace

using System;
using System.ruponentModel;
using System.IO;

namespace CipherLib {

// An Cipher component that maintains a log file.
class CipherComp : Component {
static int useID = 0;
int id; // instance id
bool isDisposed; // true if component is disposed.
FileStream log;

// Constructor
public CipherComp() {
isDisposed = false; // component not disposed
try {
log = new FileStream("CipherLog" + useID, FileMode.Create);
id = useID;
useID++;
} catch (FileNotFoundException exc) {
Console.WriteLine(exc);
log = null;
}
}

// Destructor
~CipherComp() {
Console.WriteLine("Destructor for component "
+ id);
Dispose(false);
}

// Encode the file. Return and store result.
public string Encode(string msg) {

string temp = "";

for(int i=0;i < msg.Length; i++)
temp += (char) (msg[i] + 1);

// Store in log file.
for(int i=0; i < temp.Length; i++)
log.WriteByte((byte) temp[i]);

return temp;
}

// Decode the message. Return and store result.
public string Decode(string msg) {

string temp = "";

for(int i=0; i < msg.Length; i++)
temp += (char) (msg[i] - 1);

// Store in log file.
for(int i=0; i < temp.Length; i++)
log.WriteByte((byte) temp[i]);

return temp;
}

protected override void Dispose(bool dispAll) {
Console.WriteLine("Dispose(" + dispAll +
") for component " + id);

if(!isDisposed) {
if(dispAll) {
Console.WriteLine("Closing file for " +
"component " + id);
log.Close(); // close encoded file
isDisposed = true;
}
// no unmanaged resources to release
base.Dispose(dispAll);
}
}
}
}
// Another client that uses CipherComp.

public class CipherCompClient1 {
public static void Main() {
CipherComp cc = new CipherComp();

string text = "Testing";

string ciphertext = cc.Encode(text);
Console.WriteLine(ciphertext);

string plaintext = cc.Decode(ciphertext);
Console.WriteLine(plaintext);

text = "Components are powerful.";

ciphertext = cc.Encode(text);
Console.WriteLine(ciphertext);

plaintext = cc.Decode(ciphertext);
Console.WriteLine(plaintext);

cc.Dispose(); // free resources
}
}

</source>

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

<source lang="csharp">
/*
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();
}
}

</source>

==Compare two files==

<source lang="csharp">
/*
C# A Beginner"s Guide
By Schildt
Publisher: Osborne McGraw-Hill
ISBN: 0072133295
*/
/*
Project 11-1

Compare two files.

To use this program, specify the names
of the files to be compared on the command line.

For example:
CompFile FIRST.TXT SECOND.TXT
*/

using System;
using System.IO;

public class CompFiles {
public static void Main(string[] args) {
int i=0, j=0;
FileStream f1;
FileStream f2;

try {
// open first file
try {
f1 = new FileStream(args[0], FileMode.Open);
} catch(FileNotFoundException exc) {
Console.WriteLine(exc.Message);
return;
}

// open second file
try {
f2 = new FileStream(args[1], FileMode.Open);
} catch(FileNotFoundException exc) {
Console.WriteLine(exc.Message);
return;
}
} catch(IndexOutOfRangeException exc) {
Console.WriteLine(exc.Message + "\nUsage: CompFile f1 f2");
return;
}

// Compare files
try {
do {
i = f1.ReadByte();
j = f2.ReadByte();
if(i != j) break;
} while(i != -1 && j != -1);
} catch(IOException exc) {
Console.WriteLine(exc.Message);
}
if(i != j)
Console.WriteLine("Files differ.");
else
Console.WriteLine("Files are the same.");

f1.Close();
f2.Close();
}
}

</source>

==Create a file stream with new FileStream("test.bin", FileMode.Create)==

<source lang="csharp">
using System;
using System.IO;
class MainClass {
static void Main() {
using (FileStream fs = new FileStream("test.bin", FileMode.Create)) {
using (BinaryWriter w = new BinaryWriter(fs)) {
w.Write(124.23M);
w.Write("Tstring");
w.Write("Tstring 2");
w.Write("!");
}
}
Console.WriteLine("Press Enter to read the information.");
Console.ReadLine();
using (FileStream fs = new FileStream("test.bin", FileMode.Open)) {
using (StreamReader sr = new StreamReader(fs)) {
Console.WriteLine(sr.ReadToEnd());
Console.WriteLine();
fs.Position = 0;
using (BinaryReader br = new BinaryReader(fs)) {
Console.WriteLine(br.ReadDecimal());
Console.WriteLine(br.ReadString());
Console.WriteLine(br.ReadString());
Console.WriteLine(br.ReadChar());
}
}
}
}
}
</source>

==Create StreamReader from File Stream==

<source lang="csharp">
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);
}
}
}

</source>

==FileStream with FileMode.Create and FileMode.Open==

<source lang="csharp">
using System;
using System.IO;
using System.Text;
class MainClass {
static void Main() {
using (FileStream fs = new FileStream("test.txt", FileMode.Create)) {
using (StreamWriter w = new StreamWriter(fs, Encoding.UTF8)) {
w.WriteLine(124.23M);
w.WriteLine("Test string");
w.WriteLine("!");
}
}
Console.WriteLine("Press Enter to read the information.");
Console.ReadLine();
// Open the file in read-only mode.
using (FileStream fs = new FileStream("test.txt", FileMode.Open)) {
using (StreamReader r = new StreamReader(fs, Encoding.UTF8)) {
// Read the data and convert it to the appropriate data type.
Console.WriteLine(Decimal.Parse(r.ReadLine()));
Console.WriteLine(r.ReadLine());
Console.WriteLine(Char.Parse(r.ReadLine()));
}
}
}
}

</source>

==illustrates reading and writing binary data==

<source lang="csharp">
/*
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();
}
}

</source>

==illustrates use of FileStreams==

<source lang="csharp">
/*
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();
}
}
}

</source>

==illustrates use of FileStreams 2==

<source lang="csharp">
/*
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();
}
}
}

</source>

==Reading and Writing Files==

<source lang="csharp">
using System;
using System.IO;
public class ReadingWritingFiles
{
public static void Main()
{
FileStream f = new FileStream("output.txt", FileMode.Create);
StreamWriter s = new StreamWriter(f);

s.WriteLine("{0} {1}", "test", 55);
s.Close();
f.Close();
}
}

</source>

==Reads lines separated by vertical bars==

<source lang="csharp">
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
*/

</source>

==Reads strings from a file created in a text editor==

<source lang="csharp">
using System;
using System.IO;
public class FileReadStrings {
public static void Main( ) {
String line;
StreamReader f = new StreamReader("test.data");
while((line=f.ReadLine()) != null)
Console.WriteLine(line);
f.Close();
}
}
//File: test.data
/*
4665 Street|Toronto|ON|90048
*/

</source>

==Seek from Begin==

<source lang="csharp">

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

class Program {
static void Main(string[] args) {
byte[] byData = new byte[200];
char[] charData = new Char[200];
try {
FileStream aFile = new FileStream("Program.cs", FileMode.Open);
aFile.Seek(135, SeekOrigin.Begin);
aFile.Read(byData, 0, 200);
} catch (IOException e) {
Console.WriteLine("An IO exception has been thrown!");
Console.WriteLine(e.ToString());
Console.ReadKey();
return;
}
Decoder d = Encoding.UTF8.GetDecoder();
d.GetChars(byData, 0, byData.Length, charData, 0);
Console.WriteLine(charData);
}
}
</source>

==Set File IO Permission to c:==

<source lang="csharp">
using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Permissions;

class Program {
static void Main(string[] args) {
MyClass.Method();
}
}
[FileIOPermission(SecurityAction.Assert, Read = "C:/")]
class MyClass {
public static void Method() {
// implementation goes here
}
}

</source>

==Using FileStreams==

<source lang="csharp">
/*
* C# Programmers Pocket Consultant
* Author: Gregory S. MacBeth
* Email: gmacbeth@comporium.net
* Create Date: June 27, 2003
* Last Modified Date:
* Version: 1
*/
using System;
using System.IO;
namespace Client.Chapter_11___File_and_Streams
{
public class UsingFileStreams {
static void Main(string[] args)
{
//Creates a file with read-write access that allows others to read
FileStream MyFileStream1 = new FileStream(@"c:\Projects\Testing.txt", FileMode.Create);
FileInfo MyFiles = new FileInfo(@"c:\Projects\Testing.txt");
FileStream MyFileStream2 = MyFiles.OpenRead();
//or any of the following
MyFileStream2 = MyFiles.OpenWrite();
MyFileStream2 = MyFiles.Open(FileMode.Append, FileAccess.Read, FileShare.None);
MyFileStream2 = MyFiles.Create();
//You can read file stream ona pe byte basis or as an array of bytes
int MyBytes = MyFileStream1.ReadByte();
//or
int NumberOfBytes = 200;
byte[] MyByteArray = new Byte[NumberOfBytes];
int BytesRead = MyFileStream1.Read(MyByteArray, 0, NumberOfBytes);
//Data can be written to FileStreams as well through bytes or arrays of //bytes
byte MyWriteByte = 100;
MyFileStream1.WriteByte(MyWriteByte);
//or via an array
int NumberOfBytesToWrite = 256;
byte[] MyWriteByteArray = new Byte[NumberOfBytesToWrite];
for (int i = 0; i < 256; i++)
{
MyWriteByteArray[i] = (byte)i;
i++;
}
MyFileStream1.Write(MyWriteByteArray, 0, NumberOfBytesToWrite);
MyFileStream1.Close();
MyFileStream2.Close();
}
}
}

</source>

==Write byte array to a file==

<source lang="csharp">

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
class Program {
static void Main(string[] args) {
byte[] byData;
char[] charData;
try {
FileStream aFile = new FileStream("Temp.txt", FileMode.Create);
charData = "www.nfex.ru".ToCharArray();
byData = new byte[charData.Length];
Encoder e = Encoding.UTF8.GetEncoder();
e.GetBytes(charData, 0, charData.Length, byData, 0, true);
aFile.Seek(0, SeekOrigin.Begin);
aFile.Write(byData, 0, byData.Length);
} catch (IOException ex) {
Console.WriteLine(ex.ToString());
return;
}
}
}
</source>

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