Darker Shade of the PhoneAccentBrush

Posted on October 31, 2011 by unknown

While working with a darker shade of the phoneaccentbrush, I needed to maintain the uniformity of the shade across

different PhoneAccentBrushes available. To do this, I used the PhoneAccentBrush SolidColorBrush and added the generated

brush to the application resources. Here is how I did it.

In ShadeHelper.cs,

public static SolidColorBrush getDarkerShade(SolidColorBrush brush)
        {
            SolidColorBrush darkerShade = new SolidColorBrush();
            byte alpha = 255;
            byte red = (byte)(brush.Color.R - (brush.Color.R*0.4));
            byte blue = (byte)(brush.Color.B - (brush.Color.B * 0.4));
            byte green = (byte)(brush.Color.G - (brush.Color.G * 0.4));
            darkerShade.Color = Color.FromArgb(alpha, red, green, blue);
            return darkerShade;
        }

In App.xaml.cs,

Resources.Add("PhoneDarkAccentBrush", ShadeHelper.getDarkerShade((Resources["PhoneAccentBrush"] as SolidColorBrush)));

Usage:

<TextBlock x:Name="darkAccent" Foreground={StaticResource PhoneDarkAccentBrush} Text="Darker Accent" />

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User defined variable names in ruby

Posted on October 13, 2011 by unknown

A few months back, while porting some code from php to ruby, being a newbie that I am, I came across an issue.
The php code had a function as such:

public string functionName($var1, &$var2, $var3){}

Here the caller of the function gets to decide the name of the variable ($var2).
So, the caller can access the result from a variable name of the callers choice.

functionName("variablevalue", "variableName", "variableValue");
echo $variableName;

The code was procedural and had nothing to do with classes, methods or objects.

In ruby I had to provide a similar option where the caller can name the variable.
Here is how I had implemented this.


attr_accessor :userVar, :varName

Adding a couple of properties to the class. attr_accessor defines the get set methods.

def method_missing(meth, *x)
		if "#{meth}" == self.varName
	    	class << self
		    	self
		    end.send :define_method, meth do |args|
		    	 self.userVar
		    end
		    self.send "#{meth}", x
		else
			puts "#{meth} : Such a method does not exist!"
		end
end

This checks to see if the called method exists. Uses define_method .


def methodName(var1, userVar="", var3)
		// function
		self.userVar = userVar
		self.varName = "#{self.userVar}"
		self.userVar = self.result
		return self.return
end

 objectName.methodName(var1, "myvariable", var3)
 puts objectName.myVariable

The user input variable name is a new method/property which contains the result.

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AES Encryption (ECB, PKCS5) in Windows Phone 7

Posted on October 9, 2011 by unknown

To support compatibility with some old software, I had to encrypt data with PKCS 5 padding and ECB mode with AES encryption. Awkward coder has made this a lot easier by creating a binary for windows phone 7.1 from bouncy castle. In this post I have an example of how I used the binary. Well, most of the code is from the original post by awkward coder.

public static string encrypt(string input, string password)
{
#region encrypt

var byteArray = Encoding.UTF8.GetBytes(input);
var key = Encoding.UTF8.GetBytes(password);
var encryptioncipher = CipherUtilities.GetCipher("AES/ECB/PKCS5PADDING");
encryptioncipher.Init(true, new KeyParameter(key));

//string algo = encryptioncipher.AlgorithmName;
int blocksize = encryptioncipher.GetBlockSize();

byte[] bytes = encryptioncipher.ProcessBytes(byteArray);

byte[] final = encryptioncipher.DoFinal();

string resultBytes = Encoding.UTF8.GetString(bytes, 0, bytes.Length);
MemoryStream encryptedstream = new MemoryStream(bytes.Length + final.Length);
encryptedstream.Write(bytes, 0, bytes.Length);
encryptedstream.Write(final, 0, final.Length);
encryptedstream.Flush();

byte[] encryptedData = new byte[encryptedstream.Length];
encryptedstream.Position = 0;
encryptedstream.Read(encryptedData, 0, encryptedData.Length);

//Convert to hex string
string result = HexHelper.GetHextString(encryptedData);
return result;

#endregion

}

public static string decrypt(string encryptedhexstring, string password)
{
#region decrypt

//Covert from hexstring to bytearray
byte[] encryptedData = HexHelper.GetBytes(encryptedhexstring);

var key = Encoding.UTF8.GetBytes(password);
// AES algorthim with ECB cipher & PKCS5 padding...
var cipher = CipherUtilities.GetCipher("AES/ECB/PKCS5PADDING");

// Initialise the cipher...
cipher.Init(false, new KeyParameter(key));

// Decrypt the data and write the 'final' byte stream...
var decryptionbytes = cipher.ProcessBytes(encryptedData);
var decryptedfinal = cipher.DoFinal();

// Write the decrypt bytes & final to memory...
var decryptedstream = new MemoryStream(decryptionbytes.Length);
decryptedstream.Write(decryptionbytes, 0, decryptionbytes.Length);
decryptedstream.Write(decryptedfinal, 0, decryptedfinal.Length);
decryptedstream.Flush();

var decryptedData = new byte[decryptedstream.Length];
decryptedstream.Position = 0;
decryptedstream.Read(decryptedData, 0, (int)decryptedstream.Length);

// Convert the decrypted data to a string value...
var resultdecrypted = Encoding.UTF8.GetString(decryptedData, 0, decryptedData.Length);

return resultdecrypted;

#endregion
}

Posted in encryption, windows phone 7 | Tagged , , , , | Leave a comment