C#

lukasz_nowakowski wrote:

.NET does some magic and sends data, that SQL server understands as DBNull value.

When you send a null parameter value to the server, the user must specify DBNull, not null.

bon_chan wrote:

Is it correct?

bon_chan wrote:

- foreach loop implements IEnumerable Interface

bon_chan wrote:

You implement IEnumerable for a class member and IEnumerator for a class

bon_chan wrote:

With yield keyword, you don't need to implement the members IEnumerable (Current, MoveNext(),...)

<br />
using System;<br />
using System.Collections;<br />
using System.Collections.Generic;<br />
using System.Linq;<br />
using System.Text;<br />
<br />
namespace Ch11Ex03<br />
{<br />
    public class Primes<br />
    {<br />
        private long min;<br />
        private long max;<br />
<br />
        public Primes(): this(2, 100)<br />
        {<br />
        }<br />
<br />
        public Primes(long minimum, long maximum)<br />
        {<br />
            if (min < 2)<br />
            {<br />
                min = 2;<br />
            }<br />
            else<br />
            {<br />
                min = minimum;<br />
            }<br />
            max = maximum;<br />
        }<br />
<br />
        public IEnumerator GetEnumerator()<br />
        {<br />
            for (long possiblePrime = min; possiblePrime <= max; possiblePrime++)<br />
            {<br />
                     bool isPrime = true;<br />
                     for (long possibleFactor = 2; possibleFactor <=<br />
(long)Math.Floor(Math.Sqrt(possiblePrime)); possibleFactor++)<br />
                {<br />
                    long remainderAfterDivision = possiblePrime % possibleFactor;<br />
                    if (remainderAfterDivision == 0)<br />
                    {<br />
                              isPrime = false;<br />
                              break;<br />
                    }<br />
                }<br />
                if (isPrime)<br />
                {<br />
                              yield return possiblePrime;<br />
                }<br />
            }<br />
        }<br />
    }<br />
}

<br />
class Program<br />
    {<br />
        static void Main(string[] args)<br />
        {<br />
            Primes primesFrom2To1000 = new Primes(2, 1000);<br />
            foreach (long i in primesFrom2To1000)<br />
            {<br />
                Console.Write("{0} ", i);<br />
            }<br />
            Console.ReadKey();<br />
        }<br />
    }<br />

float[] terrain = new float[10];
terrain[0] = 0.0;
terrain[1] = 0.0;
terrain[2] = 0.0;
terrain[3] = 0.5;
terrain[4] = 0.5;
terrain[5] = 0.5;
terrain[6] = 0.0;
terrain[7] = -0.5;
terrain[8] = -0.5;
terrain[9] = 0.0;

(Calling your player "Sonic" for brevity)

Note that I am saying "debounced" step to indicate that your player is not holding the forward movement button down. Your game loop needs to process ONE forward command...to explain the base case. "Holding down the button" will just loop the ONE forward command until the button is released, obviously.

KeyValuePair<int, float>[] frame = new KeyValuePair<int, float>[3];

frame[0] = new KeyValuePair<2, terrain[2]>();
frame[1] = new KeyValuePair<3, terrain[3]>();
frame[2] = new KeyValuePair<4, terrain[4]>();

//since step forward, use "next" tile.
float rotateZ = CalculateRotation(frame[1], frame[2]); //I'll leave you to figure the math. It's pretty simple though.
Sonic.Rotate(rotateZ); 

OffsetFrame(1);
Sonic.Rotate(CalculateRotation(frame[1], frame[2]));

public void OffsetFrame(int offset)
{
  frame[0] = new KeyValuePair<((int)frame[0].Key + 1), terrain[(int)frame[0].Key +1]>();
  frame[0] = new KeyValuePair<((int)frame[1].Key + 1), terrain[(int)frame[1].Key +1]>();
  frame[0] = new KeyValuePair<((int)frame[2].Key + 1), terrain[(int)frame[2].Key +1]>();

}