Fair

C#

namespace MVAP

{

    class Canvas : Panel

    {

        public class StateObject

        {

            // Client  socket.

            public Socket workSocket = null;

            // Size of receive buffer.

            public const int BufferSize = 1024;

            // Receive buffer.

            public byte[] buffer = new byte[BufferSize];

            // Received data string.

            public StringBuilder sb = new StringBuilder();

        }

        StateObject state;

        public int iPage;

        public static Socket sock;

        Timer t;

        int X, Y;

        public Canvas()

        {

            Y=X*2;

        }

        public void Close()

        {

            sock.Close();

        }

    }

}

1.  Q1  I want to change X on an instance of Canvas from another class inside the MVAP namespace.

Canvas canvas=new Canvas();

When I type

         canvas.

I expect intellisense to offer me canvas.X. Why doesn't it?

2.   Q2 When I change X from my other class, I want the canvas to calculate Y as X*2 automatically. How do I do that?

3.   Q3 I want a routine which opens sock and broadcasts a single character poll on it. I want the program to do nothing apart from accept user input after that, but if the equipment receiving the broadcast sends a response, I want the canvas instance to asynchronously receive it and act on it. How do I do that?

C

int i;

i=1;

int k;

switch (i)

{

         case 1:

                 int j=1;

         case 2:

                 int j=2;

         default:

                 j++;

                 k=j;

}

1.  Q4 Where are the compilation errors?

2.  Q5 Assuming I fix the compilation errors, what is j at the end of this?

3.  Q6 What is k at the end of this?

struct a {

         int i;

}

struct b {

         int i;

}

struct c {

         struct a *pa;

         struct b **ppb;

}

1 Q7   I want to make a new instance of struct c, which holds exactly one struct a and many struct b's. I want to expand this as and when required. How would I declare this and how would I add to it?

SPI

I have two PICs which need to communicate via SPI. The master needs to communicate at 2Mbps.

1.  Q8 How do I set the speed of the slave PIC?

2.  Q9 The master sends a single-character request to the slave, and reads back a single-character response dependant on the request. How do I achieve this without the master sending more than one byte?