Software Developer

UIButton with gradient

2012-01-13T15:04:00.003+02:00

The following code adds a gradient effect to the button:

CAGradientLayer* gradientLayer = [[CAGradientLayer alloc] init];

[gradientLayer setBounds:[buttonTest bounds]];

[gradientLayer setPosition:

CGPointMake([buttonTest bounds].size.width/2,

[buttonTest bounds].size.height/2)];

[gradientLayer setColors:

[NSArray arrayWithObjects:

(id)[[UIColor blueColor] CGColor],

(id)[[UIColor cyanColor] CGColor], nil]];

[[buttonTest layer] insertSublayer:gradientLayer atIndex:0];

[gradientLayer release];

The result may look so:

UIButton with a border

2012-01-13T14:55:00.001+02:00

Let's say, you know how to add a button to your application. Now let's add a border:

This effect should be done the code, for example in -viewDidLoad method:

- (void)viewDidLoad

{

[super viewDidLoad];

[[buttonTest layer] setCornerRadius:8.0f];

[[buttonTest layer] setMasksToBounds:YES];

[[buttonTest layer] setBorderWidth:3.0f];

}

UIButton. Change the background color in Interface Builder

2012-01-13T14:45:00.000+02:00

It could be funny, if it was not sad - it was not very easy to change the button color in Interface Builder. :) The key is the button type - set it to "Custom":

Then, you can find where to change the background color:

@synchronized

2011-12-29T09:59:00.000+02:00

In case you need to synchronize: @synchronized, NSLock, pthread, OSSpinLock showdown, done right Occasionally found this article and I think it's very helpful - in extreamely short form, as working examples, it shows all synchronization tools.

Read data from a file in the application bundle

2011-12-25T14:51:00.001+02:00

Very simple:

NSString* filePath = [[NSBundle mainBundle] pathForResource:@"Name" ofType:@"dat"];

NSData* data = [NSData dataWithContentsOfFile:filePath];

Or, in case of a text data:

NSString* filePath = [[NSBundle mainBundle] pathForResource:@"Name" ofType:@"txt"];

NSString* text = [NSString stringWithContentsOfFile:filePath

encoding:NSUTF8StringEncoding

error:nil];

Android UI vs iPhone UI

2011-12-11T06:54:00.001+02:00

I found an article talking about UI in Android and iPhone:

Why Android Will Always Be Laggier Than iOS The author says that UI tasks in Android is running in the main thread with the normal priority and only now got the hardware acceleration. The iPhone gives the high priority to the UI tasks. And it's good, etc.

Accelerometer. It's simple

2011-12-02T18:33:00.001+02:00

The simplest way to use accelerometer in an iPhone application is UIAccelerometer class:

UIAccelerometer* accelerometer = [UIAccelerometer sharedAccelerometer];

This code above shows how to get the accelerometer instance in the code.
The following line sets up the update interval:

[accelerometer setUpdateInterval: 1.0 / 10.0f];

[accelerometer setDelegate:self];

each 0.1 second the accelerometer will update the program that implements delegate method:

- (void)accelerometer:(UIAccelerometer *)acel didAccelerate:(UIAcceleration *)aceler

{

NSLog(@"acceleration.x = %+.6f", aceler.x);

NSLog(@"acceleration.y = %+.6f", aceler.y);

NSLog(@"acceleration.z = %+.6f", aceler.z);

}

Do not forget to add UIAccelerometerDelegate, for example, to a view controller class:

@interface ViewController : UIViewController <UIAccelerometerDelegate>

So here is the step-by-step scenario for beginners:

1. Create new Single-View project in Xcode.

2. In ViewController.h file add <UIAccelerometerDelegate> after UIViewController.

3. In ViewController.m file, modify viewDidLoad method:

- (void)viewDidLoad

{

[super viewDidLoad];

UIAccelerometer* accelerometer = [UIAccelerometer sharedAccelerometer];

[accelerometer setUpdateInterval: 1.0 / 10.0f];

[accelerometer setDelegate:self];

}

4. In ViewController.m file, add new method:

- (void)accelerometer:(UIAccelerometer *)acel didAccelerate:(UIAcceleration *)aceler

{

NSLog(@"acceleration.x = %+.6f", aceler.x);

NSLog(@"acceleration.y = %+.6f", aceler.y);

NSLog(@"acceleration.z = %+.6f", aceler.z);

}

This program works on iPhone. It does not make much sense to test it simulator.

Xcode 4: Add Existing Framework

2011-12-02T12:16:00.001+02:00

1. Select your project in the project navigator - on the left side of the Xcode window.
2. On the right side of the window, choose the target.
3. Choose Summary page (press on the Summary button on the top of the window).
4. Scroll down till find "Linked Frameworks and Libraries".
5. Press on plus button to add an existing framework from the list:

iOS Developer Library. Linking To A Library Or Framework.

Sort String Array

2011-11-26T23:02:00.001+02:00

The following code demonstrates how to sort an array of strings in Objective-C:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    @autoreleasepool {
        
        NSArray *stringsArray = [NSArray arrayWithObjects:
                                 @"string 1",
                                 @"String 21",
                                 @"string 12",
                                 @"String 11",
                                 @"String 02", nil];
        static NSStringCompareOptions comparisonOptions = NSCaseInsensitiveSearch | NSNumericSearch |
        NSWidthInsensitiveSearch | NSForcedOrderingSearch;
        NSLocale *currentLocale = [NSLocale currentLocale];
        NSComparator finderSort = ^(id string1, id string2) {
            NSRange string1Range = NSMakeRange(0, [string1 length]);
            return [string1 compare:string2 options:comparisonOptions range:string1Range locale:currentLocale];
        };
        
        NSArray* sortedArray = [stringsArray sortedArrayUsingComparator:finderSort];
        NSLog(@"finderSort: %@", sortedArray);        
    }
    return 0;
}

This code is taken from iOS Developer Library.

The Blocks

2011-11-26T15:24:00.001+02:00

Apple introduced blocks (a segment of code that can be executed any time) in C and Objective-c. It happened in Mac OS X 10.6. Later on this feature was back-ported to Mac OS X 10.5 and iPhone by Plausible Labs. The blocks are also called closures, because they close around variables. Also the blocks can be called lambdas.
I'd say that the blocks are the same as the regular function pointers in C. From a very general point of view, the main difference is just the symbol caret (^) before the block name instead of the asterisk (*) before the function pointer. Here is a trivial example:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    @autoreleasepool {

        void (^now)(void) = ^{ 
            NSDate* moment = [NSDate date];
            NSLog(@"Now: %@", moment);
        };
        
        
        now();
    }
    return 0;
}

The program output is: [Switching to process 41322 thread 0x0] 2011-11-26 18:07:25.202 block4[41322:707] Now: 2011-11-26 16:07:25 +0000 Program ended with exit code: 0 The following program simply creates and synchronously performs a block:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    @autoreleasepool {

        void (^theBlock)(int) = ^(int x) {
            printf("x = %d\n", x);
        };
        
        theBlock(12);
        
    }
    return 0;
}

typedef can be used with the blocks:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    @autoreleasepool {

        typedef NSInteger (^Multiply)(NSInteger, NSInteger);
        
        Multiply multiply = ^(NSInteger x, NSInteger y) 
        { 
            NSLog(@"Entering %s", __FUNCTION__);
            NSInteger z = x * y;
            return z; 
        };
        
        NSLog(@"%li * %li = %li", 5, 6, multiply(5, 6));
    }
    return 0;
}

The main purpose of the blocks is the dispatching them in Grand Central Dispatch. For example:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
    @autoreleasepool {
        printf("Hello\r");
        dispatch_queue_t queue = dispatch_get_global_queue ( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
        dispatch_sync(queue,  ^{ printf("This is the block\n"); } );
    }
    return 0;
}

and here is the output console:

[Switching to process 38217 thread 0x0]

Hello

This is the block

Program ended with exit code: 0

In a more formal way, that the block is a self-contained unit of a work, an arranged part of the source code, very similar to the C-style function. The block may contain own variables and can access the variables from outside its own lexical scope. The block can read values of variables defined in the parent scope. Variables, accessed by the block, are copied to the block data structure and can be used by the block later. It's preferred to keep these variables in the read-only format. However, the blocks can use variables declared with the keyword __block in the parent scope prepended to return data back from the blocks.

That's, actually, it. And this is an example of practical use of the blocks - enumeration of the array:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{

    @autoreleasepool {

        NSArray* array = [NSArray arrayWithObjects:@"First", @"Second", @"Third", nil];
        [array enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL* stop)
         {
             NSLog(@"%@", object);
         }];
    }
    return 0;

The following example is interesting because the block is used here as a parameter in the method of a class:

#import <Foundation/Foundation.h>

@interface Test : NSObject

- (NSInteger)calculate:(NSInteger)number withBlock:(NSInteger (^)(NSInteger))block;

@end

@implementation Test

- (NSInteger)calculate:(NSInteger)number withBlock:(NSInteger (^)(NSInteger))block
{
    NSLog(@"the number is %li", number);
    NSInteger result = block(number);
    return result;
}

@end

int main (int argc, const char * argv[])
{

    @autoreleasepool {

        Test* test = [[Test alloc] init];
        NSInteger result = [test calculate:5 withBlock:^(NSInteger number) {
            return number * number;
        }];
        NSLog(@"the result is %li", result);
        [test release];
    }
    return 0;
}

The output:

[Switching to process 41948 thread 0x0]

2011-11-26 18:33:44.383 block5[41948:707] the number is 5

2011-11-26 18:33:44.385 block5[41948:707] the result is 25

Program ended with exit code: 0

More about the blocks:
1. iOS Developer Library. A Short Practical Guide to Blocks.
2. iOS Developer Library. Blocks Programming Topics.
3. Language Specifications For Blocks.

No Longer Develop Flash for Mobile Platforms

2011-11-10T08:48:00.001+02:00

Adobe announced that it would no longer develop Flash for mobile platforms. End to mobile development bodes ill for Flash Flash to Focus on PC Browsing and Mobile Apps; Adobe to More Aggressively Contribute to HTML5

Automatic Reference Counting

2011-11-04T15:48:00.001+02:00

Automatic Reference Counting is available in Xcode 4.2. The following articles explain the ARC:

Everything you need to know about automatic reference counting (ARC)

Friday Q&A 2011-09-30: Automatic Reference Counting

Main idea:

1. no retain, release, autortelease anymore

2. strong and weak as the property classifiers instead of retain and assign

3. autorelease {} instead of NSAutoreleasePool* pool....
Probably , this is the "primary source":
Transitioning to ARC Release Notes

iOS Hardware Guide

2011-10-26T11:30:00.000+02:00

Following link shows iOS hardware available:

iOS Hardware Guide. Hardware models

The most interesting models for now:

iPhone 3GS
ARM Cortex A8, 600 MHz CPU
PowerVR SGX graphics processor
256MB of memory
3 megapixel camera with video capture capability
Speaker and microphone
Vibration support
Silent switch
GPS support
Compass support

iPhone 4
ARM Cortex-A8 Apple A4 CPU
ARM Cortex-A8 Apple A4 graphics processor
512MB of memory
Cameras
Rear 5.0 MP backside illuminated CMOS image sensor with 720p HD video at 30 fps and LED flash
Front 0.3 MP (VGA) with geotagging, tap to focus, and 480p SD video at 30 fps
Screen: 960x640 pixels, LCD at 326 ppi, 800:1 contrast ratio.
Speaker and microphone
Vibration Support
Silent switch
GPS support
Compass Support

New C++ Standard

2011-10-12T13:55:00.000+02:00

ISO published C++11 Standard: C++ language gets high marks on performance with new ISO/IEC standard

The Great

2011-10-06T08:47:00.001+02:00

Steve Jobs’ 2005 Stanford Commencement Address

Simplest serialization on iPhone

2011-08-11T11:46:00.001+03:00

The following simple program demonstrates the simplest serialization that works fine on iPhone:

#import &lt;UIKit/UIKit.h&gt;

@interface Book : NSObject&lt;NSCoding&gt;
{
    NSString *title;
    NSString *author;
}

@property (nonatomic, copy) NSString *title;
@property (nonatomic, copy) NSString *author;

@end

@implementation Book

@synthesize title, author;

- (void)encodeWithCoder:(NSCoder *)coder 
{
    [coder encodeObject:author forKey:@"author"];
    [coder encodeObject:title forKey:@"title"];
}

- (id)initWithCoder:(NSCoder *)coder {
    author = [[coder decodeObjectForKey:@"author"] retain];
    title = [[coder decodeObjectForKey:@"title"] retain];
    return self;
}

@end

BOOL Save(NSString* path)
{
    BOOL result = NO;
    if (path != nil)
    {
        Book *book = [[Book alloc] init];
        book.author = @"Leo Tolstoy";
        book.title = @"War and Peace";
        
        result = [NSKeyedArchiver archiveRootObject:book toFile:path];
        
        [book release];
    }
    return result;
}

BOOL Load(NSString *path)
{
    BOOL result = NO;
    if (path != nil)
    {
        Book *book = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
        if (book != nil)
        {
            NSLog(@"Author: %@, title: %@", book.author, book.title);
        }
    }
    return result;
}

int main(int argc, char *argv[]) 
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/books.xml"];
    NSLog(@"the path is %@", path);
    
    Save(path);

    Load(path);
    
    [pool release];
    return 0;
}

Class Book implements the protocol NSCoding and it allows to save Book object in an xml-file

Save data in XML on iPhone

2011-08-11T08:10:00.007+03:00

Seems like the simplest way to save data in the XML-format from the iPhone program is to use the NSDictionary class as it is shown in the following program:

#import <UIKit/UIKit.h>

int main(int argc, char *argv[]) {
    
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    NSLog(@"main");
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                @"First Object", @"First Key",
                                @"Second Object", @"Second Key",
                                @"Third Object", @"Third Key",
                                nil
                                ];
    
    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/test_dictionary.xml"];
    NSLog(@"the path is %@", path);
    
    BOOL result = [dictionary writeToFile: path atomically:YES];
    NSLog(@"%@", result ? @"saved" : @"not saved");
        
    [pool release];
    return 0;
}

Here is the saved file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>First Key</key>
    <string>First Object</string>
    <key>Second Key</key>
    <string>Second Object</string>
    <key>Third Key</key>
    <string>Third Object</string>
</dict>
</plist>

In order to read this file, to restore the dictionary, use this code:

if (result)
{
    NSDictionary* readData = [NSDictionary dictionaryWithContentsOfFile:path];
    for (NSString *key in readData)
        NSLog(@"%@: %@", key, [readData objectForKey: key]);
}

Here is the Console log from the program:

[Session started at 2011-08-11 08:14:39 +0300.]

2011-08-11 08:14:39.981 PListTest[37923:207] main

2011-08-11 08:14:39.983 PListTest[37923:207] the path is /Users/pgnatyuk/Library/Application Support/iPhone Simulator/4.3/Applications/3E8A25F8-345A-43D4-900D-6F248F2A5738/Documents/test_dictionary.xml

2011-08-11 08:14:39.986 PListTest[37923:207] saved

2011-08-11 08:14:39.986 PListTest[37923:207] First Key: First Object

2011-08-11 08:14:39.987 PListTest[37923:207] Third Key: Third Object

2011-08-11 08:14:39.987 PListTest[37923:207] Second Key: Second Object

Initialize C-style structures in Objective-C

2011-08-06T16:55:00.002+03:00

In order to initialize a variable of a structure type, you simply list the initial values of the structure members inside a pair of braces. For example as in the following C-program:

#include <iostream>

struct date
{
    int year;
    int month;
    int day;
};

int main (int argc, char * const argv[]) 
{
    struct date a = { 2011, 6, 8 };
    std::cout << a.year << " " << a.month << " " << a.day << "\n";
    return 0;
}

Of course this way works for Objective-C as well:

#import <Foundation/Foundation.h>

struct date 
{
    int year;
    int month;
    int day;
};

int main (int argc, const char * argv[]) 
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    struct date a = { 2011, 8, 6 };
    NSLog(@"%d %d %d", a.year, a.month, a.day);
    
    [pool drain];
    return 0;
}

Beside it, Objective-C allows to specify the structure member in such initialization list:

#import <Foundation/Foundation.h>

struct date 
{
    int year;
    int month;
    int day;
};

int main (int argc, const char * argv[]) 
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    struct date a = { .year = 2011, .month = 8, .day = 6 };
    NSLog(@"%d %d %d", a.year, a.month, a.day);
    
    [pool drain];
    return 0;
}

With this notation, specific members can be listed in any order.

How-To's for iOS

2011-08-03T15:55:00.003+03:00

Very useful link:
User Experience Coding How-To's

Cocoa. Date and Time

2011-08-02T06:58:00.001+03:00

This small program below detects the current date:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

     NSDate* today = [[NSDate alloc] init];
     NSLog(@"today is: %@", today);
    
    [today release];        
    [pool drain];
    return 0;
}

In the console you'll see:

run
[Switching to process 12401 local thread 0x3f03]
Running…
2010-03-06 17:05:45.217 DayOfToday[12401:a0f] today is: 2010-03-06 17:05:45 +0200

C#: Simplest server and client programs

2011-07-17T12:29:00.001+03:00

This is the simplest server:

using System;
using System.IO;
using System.Net.Sockets;
using System.Net;

namespace SimpleServer
{
    class SimpleListener
    {
        private void Listen()
        {
            Console.WriteLine("Start listening");

            // Listen post 50001.
            TcpListener tcpListener = new TcpListener(IPAddress.Any, 50001);
            tcpListener.Start();

            // Wait till a client comes
            while (true)
            {
                Socket newSocket = tcpListener.AcceptSocket();
                if (newSocket.Connected)
                {
                    Console.WriteLine("New client came");

                    NetworkStream networkStream = new NetworkStream(newSocket);

                    // Send a data
                    byte[] buf = { (byte)'H', (byte)'e', (byte)'l', (byte)'l', (byte)'o' };
                    networkStream.Write(buf, 0, 5);

                    networkStream.Flush();
                    networkStream.Close();

                    newSocket.Close();
                    break;
                }
            }

            Console.WriteLine("Stop listening");
            Console.Read();
        }

        static void Main(string[] args)
        {
            SimpleListener listener = new SimpleListener();
            listener.Listen();
        }
    }
}

This is the simplest client:

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;

namespace SimpleClient
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpClient newSocket = new TcpClient("localhost", 50001);

            NetworkStream networkStrem = newSocket.GetStream();

            byte[] buf = new byte[100];
            networkStrem.Read(buf, 0, 100);

            char[] buf2 = new char[100];
            for (int i = 0; i < 100; ++i)
            {
                buf2[i] = (char)buf[i];
            }

            Console.WriteLine(buf2);

            networkStrem.Close();
            newSocket.Close();

            Console.Read();
        }
    }
}

C#: Create and save a simple XML

2011-07-17T10:23:00.005+03:00

This is a simple C# program that creates a standard XML document with one element Book and saves it in a file:

using System;
using System.Text;
using System.Xml;
using System.IO;

namespace XmlTest
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlDocument xmlDocument = new XmlDocument();
            xmlDocument.PrependChild(xmlDocument.CreateXmlDeclaration("1.0", "", "yes"));
            XmlElement element = xmlDocument.CreateElement("Book");
            element.SetAttribute("author", "Leo Tolstoy");
            element.AppendChild(xmlDocument.CreateTextNode("Peace and War"));
            xmlDocument.AppendChild(element);

            StringWriter stringWriter = new StringWriter();
            XmlTextWriter xmlTextWriter = new XmlTextWriter(stringWriter);
            xmlTextWriter.Formatting = Formatting.Indented;

            xmlDocument.WriteTo(xmlTextWriter);
            xmlTextWriter.Flush();

            Console.Write(stringWriter.ToString());
            string fileName = System.Environment.GetEnvironmentVariable("TMP") + "\\Book.xml";
            xmlDocument.Save(fileName);
        }
    }
}

C#: OpenFileDialog in a console program

2011-07-14T16:49:00.009+03:00

Into a C# console program add reference for System.Windows.Forms, then, add "using System.Windows.Forms" to the program code, add [STAThread] before the Main function and now, you can use OpenFileDialog like it is shown below:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace OpenDialogTest
{
    class Program
    {
        // Make the program thread safe for COM.
        // Windows Forms should always declare the appartment style they're using.
        // http://blogs.msdn.com/b/jfoscoding/archive/2005/04/07/406341.aspx
        // This program uses a single-appartment state.
        [STAThread]
        static void Main(string[] args)
        {
            OpenFileDialog dlg = new OpenFileDialog();
            if (dlg.ShowDialog() == DialogResult.OK)
                Console.WriteLine(dlg.FileName);
            Console.ReadLine();
        }
    }
}

Or, a bit more advanced example allowing a multiselection for the image-files

using System;
using System.Text;
using System.Windows.Forms;

namespace OpenDialogMultiSelectTest
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            OpenFileDialog dlg = new OpenFileDialog();
            dlg.Multiselect = true;
            dlg.Title = "Choose few files";
            dlg.Filter = "Images|*.jpg|AllFiles|*.*";
            if (dlg.ShowDialog() == DialogResult.OK)
            {
                foreach(string str in dlg.FileNames)
                {
                    Console.WriteLine(str);
                }
            }
        }
    }
}

Or a bit more practical example - create a backup copy of a selected file:

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

namespace FileStreamTest
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Title = "Select a file to copy";
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                FileStream inStream = File.OpenRead(ofd.FileName);
                FileStream outStream = File.OpenWrite(ofd.FileName + ".bak");

                bool cont = true;
                do
                {
                    int b =  inStream.ReadByte();
                    cont = (b > -1);
                    if (cont)
                        outStream.WriteByte((byte)b);
                }
                while (cont);

                outStream.Flush();
                outStream.Close();

                inStream.Close();
            }
        }
    }
}

Or, let's use MemoryStream:

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

namespace MemoryStreamTest
{
    class Program
    {
        public static void SaveMemoryStream(MemoryStream ms, string fileName)
        {
            FileStream outStream = File.OpenWrite(fileName);
            ms.WriteTo(outStream);
            outStream.Flush();
            outStream.Close();
        }

        [STAThread]
        static void Main(string[] args)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                FileStream inStream = File.OpenRead(ofd.FileName);
                MemoryStream ms = new MemoryStream();
                ms.SetLength(inStream.Length);
                inStream.Read(ms.GetBuffer(), 0, (int)inStream.Length);
                ms.Flush();
                inStream.Close();
                SaveMemoryStream(ms, ofd.FileName + ".bak");
                ms.Close();
            }
        }
    }
}

Actionscript undefined

2011-05-28T23:21:00.002+03:00

undefined is a type: typeof(undefined) returns "undefined" - a string, the type name.
This type (undefined) has only one value and this value is undefined, that means that a variable or a parameter or a return value, that was declared without the type name, has not been assigned to any value yet.
Also an array element becomes undefined if instruction delete is applied for it.
Typed variables cannot be undefined. Undefined is equal to null, if operator == is used. For operator === undefined and null are not equal:
trace(null == undefined); //true
trace(null === undefined); //false
Actionscript Dictionary

Random String Generator (C#)

2011-05-25T16:22:00.001+03:00

In case someone else needs it

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace RandomStringGenerator
{
    class Program
    {
        private static Random rnd = new Random();

        static void Main(string[] args)
        {
            Console.WriteLine("Random string (1): {0}", Generate(1));
            Console.WriteLine("Random string (2): {0}", Generate(2));
            Console.WriteLine("Random string (4): {0}", Generate(4));
            Console.WriteLine("Random string (10): {0}", Generate(10));
            Console.WriteLine("Random string (32): {0}", Generate(32));
            Console.WriteLine("Random string (64): {0}", Generate(64));
        }

        static string Generate(int size)
        {
            StringBuilder str = new StringBuilder();
            for (int i = 0; i < size; ++i)
            {
                char ch = Convert.ToChar(rnd.Next(32, 128));
                str.Append(ch);
            }
            return str.ToString();
        }
    }
}