طلب مساعدة في حل هذه المشكلة

public static void SetLicence (string strKey)

{

string str = "";
string str2 = "";
string str3 = "";
string str4 = ""; 
if ((strKey != "") && (strKey.Length == 0x23))
{
StringBuilder builder = new StringBuilder();
for (int i = 0; i < strKey.Length; i++)
{
if ((strKey > 'F') && (strKey < '['))
{
builder.Append('0');
}
else
{
builder.Append(strKey);
}
}
strKey = builder.ToString();
str = strKey.Substring(0, 8);
strKey = strKey.Replace(str + "-", "");
str2 = strKey.Substring(0, 8);
strKey = strKey.Replace(str2 + "-", "");
str3 = strKey.Substring(0, 8);
strKey = strKey.Replace(str3 + "-", "");
str4 = strKey;
long num2 = 0L;
num2 += Convert.ToInt32(str.Substring(0, 3), 0x10);
num2 += Convert.ToInt32(str2.Substring(0, 3), 0x10);
num2 += Convert.ToInt32(str3.Substring(0, 3), 0x10);
if (num2 == Convert.ToInt32(str4, 0x10))
{
FileVersionInfo versionInfo = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location);
string str5 = Convert.ToInt32(str.Substring(0, 6), 0x10).ToString();
if ((versionInfo.FileMajorPart.ToString("0") + versionInfo.FileMinorPart.ToString("00")) == str5.Substring(0, 3))
{
string code = GetCode();
long num3 = 0L;
for (int j = 0; j < code.Substring(6).Length; j++)
{
num3 += (long) code.Substring(6)[j];
}
if (Convert.ToInt32(str2, 0x10) == ((num3 * 0x3e7L) % 0x7fffffffL))
{
MessageBox.Show("Good Work!!!!"); 
}
}
}
}
if (menmLicenseType == LicenseType.Demo)
{
MessageBox.Show("Try again!!!!");
}

}

you may need to use randomization to Auto generate numbers

check this example from MSDN

// Example of the Random class constructors and Random.NextDouble( ) 
// method.
using System;
using System.Threading;

public class RandomObjectDemo  
{
	// Generate random numbers from the specified Random object.
	static void RunIntNDoubleRandoms( Random randObj )
	{
		// Generate the first six random integers.
		for( int j = 0; j < 6; j++ )
			Console.Write( " {0,10} ", randObj.Next( ) );
		Console.WriteLine( );

		// Generate the first six random doubles.
		for( int j = 0; j < 6; j++ )
			Console.Write( " {0:F8} ", randObj.NextDouble( ) );
		Console.WriteLine( );
	}

	// Create a Random object with the specified seed.
	static void FixedSeedRandoms( int seed )
	{
		Console.WriteLine( 
			"\nRandom numbers from a Random object with " +
			"seed = {0}:", seed );
		Random fixRand = new Random( seed );

		RunIntNDoubleRandoms( fixRand );
	}

	// Create a random object with a timer-generated seed.
	static void AutoSeedRandoms( )
	{
		// Wait to allow the timer to advance.
		Thread.Sleep( 1 );

		Console.WriteLine( 
			"\nRandom numbers from a Random object " +
			"with an auto-generated seed:" );
		Random autoRand = new Random( );

		RunIntNDoubleRandoms( autoRand );
	}

	static void Main( )
	{	
		Console.WriteLine(
			"This example of the Random class constructors and " +
			"Random.NextDouble( ) \n" +
			"generates the following output.\n" );
		Console.WriteLine(
			"Create Random objects, and then generate and " +
			"display six integers and \nsix doubles from each.");

		FixedSeedRandoms( 123 );
		FixedSeedRandoms( 123 );

		FixedSeedRandoms( 456 );
		FixedSeedRandoms( 456 );

		AutoSeedRandoms( );
		AutoSeedRandoms( );
		AutoSeedRandoms( );
	}
}

hope this help

الرجاء المزيد من المساعدة وشكرا مسبقا !!!!!