Like you can see above in the image, it just looks awesome!

To achieve this, I followed a couple of simple steps:

• Create a cool button image, where you want the circle progressbar to appear in
• Find out the center and radius of the circle progressbar, you can do this either by using an image editor or just guess some values and tweak them when they are not completely perfect.
• Create a class subclassing a UIView, which has 2 properties : MaxValue (the value that is the maximum you want to use) and Progress (what is the current progress of the progressbar)
• Put it all on another View and change the Progress property when the progress of your process changes

//
//  SBCircleProgressBar.h
//
//  Created by Wim Haanstra on 17-11-11.
//  Copyright (c) 2011 Sorted Bits. All rights reserved.
//

@interface SBCircleProgressBar : UIView

// The maximum value of the progressbar
@property (nonatomic) float MaxValue;

// The current value of the progressbar
@property (nonatomic) float Progress;

@end

//
//  SBCircleProgressBar.m
//
//  Created by Wim Haanstra on 17-11-11.
//  Copyright (c) 2011 Sorted Bits. All rights reserved.
//

#import "SBCircleProgressBar.h"

@implementation SBCircleProgressBar

@synthesize MaxValue, Progress;

// SOME VALUES YOU CAN CHANGE TO CHANGE THE BEHAVIOUR OF THE PROGRESSBAR
#define MAX_DEGREES	360
#define START_DEGREES	270

// Define the radius that the circle needs
#define CIRCLE_RADIUS	27

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {

		self.backgroundColor = [UIColor clearColor];
		self.userInteractionEnabled = NO;

		// Default values for the progress bar
		self.MaxValue = 100.0f;
		self.Progress = 0.0f;

    }
    return self;
}

- (void) setMaxValue:(float) _MaxValue
{
	MaxValue = _MaxValue;
	[self setNeedsDisplay];
}

- (void) setProgress:(float) _Progress
{
	Progress = _Progress;
	[self setNeedsDisplay];
}

- (void)drawRect:(CGRect)rect
{
	CGContextRef context = UIGraphicsGetCurrentContext(); 

	// Set the color of the circle to appear for the progressbar
    CGContextSetRGBStrokeColor(context, 0.341, 0.635, 0.961, 0.6); 

	// Set the line width of the circle to appear
    CGContextSetLineWidth(context, 10.0); 

	// Calculate the middle of the circle
	CGPoint circleCenter = CGPointMake(self.frame.size.width / 2, self.frame.size.height / 2);

	// Calculate the amount of degrees the circle needs to have filled
	float currentDegrees = (MAX_DEGREES / self.MaxValue) * self.Progress;

	// Draw the ARC (part of the circle
	CGContextAddArc(context, circleCenter.x , circleCenter.y, CIRCLE_RADIUS, radians(START_DEGREES), radians(START_DEGREES + currentDegrees), 0); 
	CGContextStrokePath(context);
}


@end

You need to put this view OVER the image of your button. Because we do this, we also set userInteractionEnabled otherwise you wouldn’t be able to push your button anymore, because the progressbar would catch all the touches.

The method “radians” you see in there, is a small inline method used to calculate degrees to radians:

static inline float radians(double degrees) { return degrees * M_PI / 180; }

There are some methods I use regularly and most of them apply to the string class. So without further ado, here are some of my favorites.

Validating

public static bool IsInt(this string text)
{
    int integer = 0;
    return Int32.TryParse(text, autoload =  out integer);
}

Of course you can create methods like this for all kind of types to support. This one just shows an example for the Int32 type. This way I can easily check if variables are correct. It is too bad that you can’t just parse the variable into the void so an extra variable is needed.

One other is an extension to make a valid filename from a string, like this:

static public string ToValidFileName(this string name)
{
    string invalidChars = Regex.Escape(new string(Path.GetInvalidFileNameChars()));
    string invalidReStr = string.Format(@"[{0}]+", invalidChars);
    return Regex.Replace(name, invalidReStr, "_");
} 

Hashing
There are several reasons to hash a string, I personally use it to store passwords. Nowadays I use SHA1 hashing because MD5 is not that secure.

public static string ToSHA1(this string text, Encoding enc)
{
    byte[] buffer = enc.GetBytes(text);
    SHA1CryptoServiceProvider cryptoTransformSHA1 =
    new SHA1CryptoServiceProvider();
    string hash = BitConverter.ToString(
    cryptoTransformSHA1.ComputeHash(buffer)).Replace("-", "");
    return hash;
}

public static string ToMD5(this string input)
{
    MD5 md5 = System.Security.Cryptography.MD5.Create();
    byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
    byte[] hash = md5.ComputeHash(inputBytes);
    StringBuilder sb = new StringBuilder();

    for (int i = 0; i < hash.Length; i++)
    {
        sb.Append(hash[i].ToString("X2"));
    }
    return sb.ToString();
} 

Encrypting/Decrypting
Encrypting and decrypting data is very important in one of my latest projects. For that reason I created these 2 extension methods. They encrypt and decrypt a string with a supplied passphrase. If there was no passphrase supplied, it will try to fetch one from the .config file.

public static string Encrypt(this string Message, string passphrase = "")
{
	if (passphrase == "")
		passphrase = ConfigurationManager.AppSettings["encrpytionPassphrase"];

	byte[] Results;
	System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();

	MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
	byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(passphrase));

	TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();

	TDESAlgorithm.Key = TDESKey;
	TDESAlgorithm.Mode = CipherMode.ECB;
	TDESAlgorithm.Padding = PaddingMode.PKCS7;

	byte[] DataToEncrypt = UTF8.GetBytes(Message);

	try
	{
		ICryptoTransform Encryptor = TDESAlgorithm.CreateEncryptor();
		Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length);
	}
	finally
	{
		TDESAlgorithm.Clear();
		HashProvider.Clear();
	}

	return Convert.ToBase64String(Results);
}

public static string Decrypt(this string Message, string passphrase = "")
{
	if (passphrase == "")
		passphrase = ConfigurationManager.AppSettings["encrpytionPassphrase"];
	if (Message == string.Empty)
		return string.Empty;

	byte[] Results;
	System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();

	MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
	byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(passphrase));

	TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();

	TDESAlgorithm.Key = TDESKey;
	TDESAlgorithm.Mode = CipherMode.ECB;
	TDESAlgorithm.Padding = PaddingMode.PKCS7;

	byte[] DataToDecrypt = Convert.FromBase64String(Message);

	try
	{
		ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
		Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length);
	}
	catch
	{
		Results = new byte[0];
	}
	finally
	{
		TDESAlgorithm.Clear();
		HashProvider.Clear();
	}

	return UTF8.GetString(Results);
}

So, I made an array of NSString objects that I wanted to lay out, around that circle.

NSArray* sections = [[NSArray alloc] initWithObjects:@"text1", @"text2", @"text3", @"text4", nil];

- (UIImage*) createMenuRingWithFrame:(CGRect)frame
{
    // First fix the frame to make sure it uses the right scaling (iPhone 4 / iPad compatibility).
	frame = CGRectMake(frame.origin.x, frame.origin.y, frame.size.width * scale, frame.size.height * scale);

    // Same for the text radius
	float scaledTextRadius = textRadius * scale;
	float scaledRingWidth = ringWidth;

    // Define the centerpoint of the circle.
	CGPoint centerPoint = CGPointMake(frame.size.width / 2, frame.size.height / 2);

    // self.menuItemsFont is of the type UIFont, which I use to get the font for displaying the text on the circle.
	char* fontName = (char*)[self.menuItemsFont.fontName cStringUsingEncoding:NSASCIIStringEncoding];

    // 2 UIColor's, which I need for the color of the circle and for the text
	ringColor = [UIColor colorWithRed:1 green:1 blue:1 alpha:0.7];
	textColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:1];

	CGFloat* ringColorComponents = (float*)CGColorGetComponents(ringColor.CGColor);
	CGFloat* textColorComponents = (float*)CGColorGetComponents(textColor.CGColor);

	CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, frame.size.width, frame.size.height, 8, 4 * frame.size.width, colorSpace, kCGImageAlphaPremultipliedFirst);

	CGContextSetTextMatrix(context, CGAffineTransformIdentity);

	CGContextSelectFont(context, fontName, 18 * scale, kCGEncodingMacRoman);
	CGContextSetRGBStrokeColor(context, ringColorComponents[0], ringColorComponents[1], ringColorComponents[2], ringAlpha);
	CGContextSetLineWidth(context, scaledRingWidth);

	CGContextStrokeEllipseInRect(context, CGRectMake(scaledRingWidth, scaledRingWidth, frame.size.width - (scaledRingWidth * 2), frame.size.height - (scaledRingWidth * 2)));
	CGContextSetRGBFillColor(context, textColorComponents[0], textColorComponents[1], textColorComponents[2], textAlpha);

	CGContextSaveGState(context);
	CGContextTranslateCTM(context, centerPoint.x, centerPoint.y);

    // define the angles of the texts to divide them evenly on the circle.
	float angleStep = 2 * M_PI / [sections count];

    // I set the starting-angle on 90 degrees, to make sure the first text was ON TOP of the circle.
	float angle = degreesToRadians(90);

    // Some custom text-radius fixing (and scaling for iPhone 4 & iPad). To make sure my text centered nicely.
	scaledTextRadius = scaledTextRadius - 12 * scale;

    // Loop through texts and draw them at the appropriate angle.
	for (NSString* text in sections)
	{
        // call a method that actually draws the text at an angle
		[self drawStringAtContext:context string:text atAngle:angle withRadius:scaledTextRadius];
		angle -= angleStep;
	}

	CGContextRestoreGState(context);

	CGImageRef contextImage = CGBitmapContextCreateImage(context);

    // Release the stuff to avoid memory leaks.
	CGContextRelease(context);
	CGColorSpaceRelease(colorSpace);

    return [UIImage imageWithCGImage:contextImage];

}

// This method draws the text at an angle, while the location is based on the radius + angle.
- (void) drawStringAtContext:(CGContextRef) context string:(NSString*) text atAngle:(float) angle withRadius:(float) radius
{
	// Scale the fontsize to match UIScreen scaling
	UIFont* scaledMenuItemsFont = [menuItemsFont fontWithSize:18 * scale];

	// Get the size of the string when it would be drawn with the selected font
	CGSize textSize = [text sizeWithFont:scaledMenuItemsFont];

	float perimeter = 2 * M_PI * radius;

	// determine the angle of the text.
	float textAngle = (textSize.width) / perimeter * 2 * M_PI;
	angle += textAngle / 2;

	// We loop through each letter in the string, so we can set the angle for each letter right
	for (int index = 0; index < [text length]; index++)
	{
	    // Get the correct letter by the index
		NSRange range = {index, 1};
		NSString* letter = [text substringWithRange:range];
		char* c = (char*)[letter cStringUsingEncoding:NSASCIIStringEncoding];
		CGSize charSize = [letter sizeWithFont:scaledMenuItemsFont];

	    // Determin the X and Y position of the letter based on the angle and the radius
		float x = radius * cos(angle);
		float y = radius * sin(angle);

		float letterAngle = (charSize.width / perimeter * -2 * M_PI);

	    // Save the state of the context, because rotations are based on the original origin
		CGContextSaveGState(context);
		CGContextTranslateCTM(context, x, y);
	    // Rotate the canvas so we can just draw our text horizontally
		CGContextRotateCTM(context, (angle - 0.5 * M_PI));
		CGContextShowTextAtPoint(context, 0, 0, c, strlen(c));
	    // Restore the context again.
		CGContextRestoreGState(context);

		angle += letterAngle;
	}
}

I came to this solution after I asked a question on StackOverflow, which was helpfully demonstrated by Dribbel on how to do it. Credits for that to him.

For example, sometimes you receive a string like this: Terminator_2$003A_Judgment_Day. I wanted to convert the weird encoding they use, so I wrote a piece of code for that. It might be that this could be encoded some other way and then I would like to hear from you, but here is my code:

+ (NSString*) replaceHexInString:(NSString*) value
{
	NSRange range = [value rangeOfString:@"$00"];

	while (range.location != NSNotFound)
	{
		if (range.location + 5 <= [value length])
		{
			NSString* hexValue = [value substringFromIndex:range.location];
			hexValue = [hexValue substringToIndex:5];
			NSString* newHexValue = [hexValue stringByReplacingOccurrencesOfString:@"$" withString:@"0x"];

			unsigned int dec;
			NSScanner *scan = [NSScanner scannerWithString:newHexValue];

			if ([scan scanHexInt:&dec])
			{
				NSString* convertedValue = [NSString stringWithFormat:@"%c", dec];
				value = [value stringByReplacingOccurrencesOfString:hexValue withString:convertedValue];
			}
		}

		range = [value rangeOfString:@"$00"];
	}
	return value;
}

I know this probably does not get the UTF-16 characters, but in my case I (hope to) know they won’t use them.

Well, that’s about it. Not sure if anyone can use this, but I do .

After comparing a bit, I came to NLog and tried integrating this in my project. My project being build in Visual Studio 2010 has support for those nice web.config’s that can be transformed/malformed/adjusted while publishing. This was very necessary because my debug (local) build uses a different SQL instance than my production build.

So I just wanted to show you how I configured NLog in my web.config. It might be obvious for some people, but for others it might not.

In my normal web.config I added the following lines. First I added a new section row to my configSections.

After that I went and added the normal NLog configuration to my web.config.

 insert into Log (TimeStamp, Level, Logger, Message, UserIdentity, CallSite) values(@time_stamp, @level, @logger, @message, @useridentity, @callsite);

This is the information for my debug environment. Because my laptop run SQL express, it connects to that instance.

This is my web.config.release :

It changes the connectionstring when I publish my release version. I love that feature of Visual Studio 2010!

So I looked in queueing the downloads and tried (ofcourse) writing my own QueueHandler class. After I written and spend a couple of hours bughunting/testing my QueueuHandler, I came to the awesome idea to see what the iPhone SDK supplies for this kind of jobs (you DO read my sarcasm, dont you?).

I am using ASIHTTPRequest for my web-requests in WallPaper. I will just show you how I queue my downloads and when the download finishes, I put the image in a predefined and created UIImageView.

I first declare a couple of variables in my .h file.

NSMutableArray* downloadQueue;
NSOperationQueue* queue;

I added some UIImageView’s to a view and I put them and the download URL in a NSMutableDictionary, like this:

NSMutableDictionary* threadArguments = [[NSMutableDictionary alloc] init];

[threadArguments setObject:myUrl forKey:@"url"];
[threadArguments setObject:myImageView forKey:@"iv"];

[self addToDownloadQueue:threadArguments];

The addToDownloadQueue method does something like this after that (threadArguments is the parameter the method is receiving).

// Add the object to the NSMutableArray I got stored.
[downloadQueue addObject:threadArguments];
if (!queue)
{
	queue = [[NSOperationQueue alloc] init];
	[queue setMaxConcurrentOperationCount:1];
}

NSString* threadUrl = [threadArguments valueForKey:@"url"];
NSURL* downloadUrl = [NSURL URLWithString:threadUrl];
ASIHTTPRequest* request = [ASIHTTPRequest requestWithURL:downloadUrl];
[request setDelegate:self];
[request setDidFinishSelector:@selector(downloadDone:)];
[request setDidFailSelector:@selector(downloadFailed:)];

I put the MaxConcurrentOperationCount on 1 to make sure the application sends the requests for thumbnails one by one (going easy on your bandwidth and on my server).

Now we need to implement the FinishSelector and the FailSelector methods to catch the downloads that are finished and put the downloaded image in the pre-created UIImageView.

- (void)downloadFailed:(ASIHTTPRequest *)request
{
	NSLog(@"Downloading failed?");
}

- (void)downloadDone:(ASIHTTPRequest *)request
{
	NSString* downloadUrl = [request.url absoluteString];

	NSMutableDictionary* foundObj = nil;

	for (NSMutableDictionary* dict in downloadQueue)
	{
		NSString* queueUrl = [dict valueForKey:@"url"];

		if ([downloadUrl isEqualToString:queueUrl])
		{
			UIImageView* iv = (UIImageView*)[dict valueForKey:@"iv"];
			NSData* imageData = request.rawResponseData;

			if (iv != nil)
				iv.image = [UIImage imageWithData:imageData];

			foundObj = dict;
		}
	}

	if (foundObj != nil)
		[downloadQueue removeObject:foundObj];
}

*Ok, somehow my code syntax highlighting screws up the indenting.*

Well, I hope you can use something of my weird code.

I just will be posting my code here, to let you see how I solved the problem.
First, my JavaScript code to show the dialog I want:

function showDialog(ID) {
	var dlg = $("#" + ID).dialog({
		bgiframe: true,
		height: 165,
		width: 450,
		modal: true,
		buttons: {
			Ok: function() {
			$(this).dialog('close');
			__doPostBack = newDoPostBack;
			 __doPostBack("aspnetForm", null);
			},
			Cancel: function() {
				$(this).dialog('close');
			}
		}
	});
	dlg.parent().appendTo(jQuery('form:first'));
}

function newDoPostBack(eventTarget, eventArgument) {
	var theForm = document.forms[0];

	if (!theForm) {
		theForm = document.aspnetForm;
	}

	if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
		document.getElementById("__EVENTTARGET").value = eventTarget;
		document.getElementById("__EVENTARGUMENT").value = eventArgument;
		theForm.submit();
	}
}

Now here is my simple dialog, and the code to initiate it.

		Please enter a server name here. It can be anything you like:

Well there is no real solution for this kind of problem, at least not one I could find. So I created a ConfigManager class which can replace the ConfigurationManager class.

So what does the ConfigManager class do?

So, actually it does nothing more than just extend the normal ConfigurationManager.

Usage:

string indexDirectory = ConfigManager.AppSettings["IndexDirectory"];
string connection = ConfigManager.ConnectionStrings["DatabaseConnection"];

I also created a small method that can output all active settings in an HTML string:

string html = ConfigManager.PresentContents();

Sample web.config:

...

...

Sample ~/Configurations/MyComputer.config:

The MyComputer.config file is only loaded if the application is run on a machine with the name ‘MyComputer’. When it IS run on that machine, the IndexDirectory configuration setting from the web.config is overridden by the IndexDirectory setting from the MyComputer.config.

ConfigManager v2 1.0
ConfigManager v2 1.0 Help File

I wrote the backend of my iPhone app in C# 3.5, using LINQ and Ajax, so this application wouldn’t run on the MyDomain.com hosting. I knew this before I took the hosting, but still… I love LINQ and I want to use it!

So, I actually was thinking, how do I get this to run? Well it is easier then I thought. All you need to do is precompile your application locally and upload it to your hosting.

I am precompiling using a small batch file I wrote:

md %2
C:WindowsMicrosoft.NETFrameworkv2.0.50727aspnet_compiler.exe -p %1 -v / %2


The batch accepts 2 parameters. Parameter 1 is the location of your project sources and the 2nd parameter is the directory where you want to store your precompiled app.

After I uploaded the precompiled app, I still received a few errors about DLL’s not found, so I actually copied some 3.5 based DLL’s from my Windows GAC.

Here’s the list of DLL’s I had to copy, it could be that you need a different set of DLL’s based on the functionality you used.

System.Core.dll
System.Data.DataSetExtensions.dll
System.Data.Linq.dll
System.Web.dll
System.Web.Extensions.dll
System.Xml.Linq.dll


Those were all the files I needed to get Linq up and running .

The code that I find mostly is the following (I editted a bit, to match my coding style):

Global.asax
[csharp] protected void Application_Start(object sender, EventArgs e)
{
Application["SessionCount"] = 0;
}

protected void Session_Start(object sender, EventArgs e)
{
Application.Lock();

int sessionCount = 0;

if (Int32.TryParse(Application["SessionCount"].ToString(), out sessionCount))
sessionCount++;

Application["SessionCount"] = sessionCount;
Application.UnLock();
}

protected void Session_End(object sender, EventArgs e)
{

Application.Lock();

int sessionCount = 0;

if (Int32.TryParse(Application["SessionCount"].ToString(), out sessionCount))
sessionCount–;

Application["SessionCount"] = sessionCount;
Application.UnLock();
}
[/csharp]

The thing I am wondering about is, what happens when the site gets a lot of load. Does locking the Application object make the site slower? Because I noticed that when you lock the Application object, no pages get served to users.

What happens with multi-threaded web applications? Are all threads blocked during the lock?

I don’t know the answer yet, but I think this is a nice thing to try to find out.