Here is my code for the main program form:

 1 using System; 2 using System.Collections.Generic;
 3 using System.Collections;
 4 using System.ComponentModel;
 5 using System.Data;
 6 using System.Drawing;
 7 using System.Text;
 8 using System.Windows.Forms;
 9 
10 namespace ImageServer
11 {
12     public partial class FormMain : Form
13     {
14         ImageServerAPI isAPI;
16         public delegate void dStatusUpdate(string message);
16         public dStatusUpdate statusUpdate;
17         ArrayList cats;
18         ArrayList imgs;
19 
20         public FormMain()
21         {
22             InitializeComponent();
23         }
24 
25         private void FormMain_Load(object sender, EventArgs e)
26         {
27             comboServerIP.SelectedIndex = 0;
28             listImages.Items.Clear();
29             comboServerIP.Focus();
30             labelStatus.Text = "Started, awaiting orders...";
31             statusUpdate = new dStatusUpdate(displayMessage);
32             isAPI = new ImageServerAPI(this);
33         }
34 
35         private void buttonGetCategory_Click(object sender, EventArgs e)
36         {
37             comboCategory.Items.Clear();
38             cats = isAPI.getCategoriesList(comboServerIP.Text);
39             for (int i = 0; i < cats.Count; i++)
40             {
41                 comboCategory.Items.Add("(" + ((Category)(cats[i])).cId + ") " + ((Category)(cats[i])).cName);
42             }
43         }
44 
45         public void displayMessage(string message)
46         {
47             labelStatus.Text = message;
48             labelStatus.Refresh();
49         }
50 
51         private void buttonGetImage_Click(object sender, EventArgs e)
52         {
53             listImages.Items.Clear();
54             imgs = isAPI.getImagesList(comboServerIP.Text, ((Category)cats[comboCategory.SelectedIndex]).cId);
55             for (int i = 0; i < imgs.Count; i++)
56             {
57                 listImages.Items.Add("(" + ((Img)(imgs[i])).cId + ") " + ((Img)(imgs[i])).cName);
58             }
59             listImages.Refresh();
60         }
61 
62         public String getServer()
63         {
64             return comboServerIP.Text;
65         }
66 
67         public void addResponse(String str)
68         {
69             textXML.Text += str;
70             textXML.Refresh();
71         }
72 
73         public void setResponse(String str)
74         {
75             textXML.Text = str;
76             textXML.Refresh();
77         }
78 
79         private void listImages_MouseDoubleClick(object sender, MouseEventArgs e)
80         {
81             int id = listImages.SelectedIndices[0];
82             Bitmap img = isAPI.getImage(comboServerIP.Text, ((Img)imgs[id]).cId);
83             //Bitmap img = new Bitmap("G:SchoolCN3670labsImageServerImageClient1.bmp");
84             FormImage frmImage = new FormImage(img, ((Img)imgs[id]).cName);
85             frmImage.Show();
86         }
87     }
88 }

My code for the image form is as follows:

 1 using System; 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Text;
 7 using System.Windows.Forms;
 8 
 9 namespace ImageServer
10 {
11     public partial class FormImage : Form
12     {
13         Bitmap img;
14 
15         public FormImage(Bitmap img, String name)
16         {
17             InitializeComponent();
18             this.image.Image = img;
19             this.Text = name;
20         }
21 
22         public FormImage()
23         {
24             InitializeComponent();
25         }
26 
27         private void FormImage_Load(object sender, EventArgs e)
28         {
29             this.image.Refresh();
30         }
31     }
32 }

For the XML handling and sending:

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Collections;
  4 using System.Text;
  5 using System.Net;
  6 using System.Net.Sockets;
  7 using System.Xml;
  8 using System.Drawing;
  9 using System.IO;
 10 
 11 namespace ImageServer
 12 {
 13     class ImageServerAPI
 14     {
 15         FormMain form;
 16         private Socket currentSocket;
 17         private IPAddress currentAddress;
 18         private static int PORT = 10000;
 19         private int state;
 20         private static int StateNewCategory = 1;
 21         private static int StateCategoryListRequest = 2;
 22         private static int StateCategoryListComplete = 3;
 23 
 24         private static int StateImageSession = 4;
 25         private static int StateImageListRequest = 5;
 26         private static int StateImageListComplete = 6;
 27 
 28         private static int StateGetSession = 7;
 29         private static int StateGetImage = 8;
 30         private static int StateGetComplete = 9;
 31 
 32         public ImageServerAPI(FormMain frm)
 33         {
 34             form = frm;
 35             state = StateNewCategory;
 36         }
 37 
 38         public int sendString(string send) {
 39             int counter = 0;
 40 
 41             Byte[] sendBytes = Encoding.ASCII.GetBytes(send);
 42             Byte[] nullByte = new Byte[] { 0 };
 43             int length = sendBytes.Length;
 44             int sendLength = send.Length;
 45             int sendIndex = 0;
 46             try
 47             {
 48                 if (currentSocket == null || !currentSocket.Connected)
 49                 {
 50                     return -1;
 51                 }
 52                 while (sendIndex < sendLength)
 53                 {
 54                     counter = currentSocket.Send(sendBytes, sendIndex, length, 0);
 55                     sendIndex += counter;
 56                 }
 57 
 58                 counter = currentSocket.Send(nullByte, 1, 0);
 59             }
 60             catch (SocketException se)
 61             {
 62                 return -1;
 63             }
 64             return sendIndex;
 65         }
 66 
 67         public String getResponse()
 68         {
 69             String recieve = "";
 70             try
 71             {
 72                 byte[] buffer = new byte[1];
 73                 int count = 0;
 74                 do
 75                 {
 76                     count += currentSocket.Receive(buffer, 1, SocketFlags.None);
 77                     recieve += Encoding.ASCII.GetString(buffer);
 78                 } while (buffer[0] != 0);
 79                 //Fixing this
 80 
 81             }
 82             catch (SocketException se)
 83             {
 84                 return "";
 85             }
 86             return recieve;
 87         }
 88 
 89         public ArrayList getCategoriesList(String server) {
 90             ArrayList lst = new ArrayList();
 91             form.displayMessage("Fetching Categories List");
 92             currentSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
 93             IPHostEntry IPHost = Dns.GetHostEntry(server);
 94             IPEndPoint ipServer = new IPEndPoint(IPHost.AddressList[0].Address, PORT);
 95             currentSocket.Connect(ipServer);
 96 
 97             String sendString = "<ReqSession>dallin</ReqSession>";
 98             this.sendString(sendString);
 99             String res = this.getResponse();
100             form.setResponse(res);
101             sendString = "<CategoryListRequest />";
102             this.sendString(sendString);
103             res = this.getResponse();
104             form.setResponse(res);
105             //TODO: parse XML
106             XmlDocument xml = new XmlDocument();
107             xml.LoadXml(res);
108 
109             lst.AddRange(this.DomtoCategory(xml.DocumentElement, 0));
110 
111             sendString = "<Complete />";
112             this.sendString(sendString);
113             res = this.getResponse();
114             currentSocket.Disconnect(false);
115             currentSocket.Close();
116 
117             form.displayMessage("Categories List recieved");
118             return lst;
119         }
120 
121         private ArrayList DomtoImage(XmlNode parentNode, int level)
122         {
123             ArrayList list = new ArrayList();
124 
125             foreach (XmlNode domChild in parentNode.ChildNodes)
126             {
127                 String name = "";
128                 String id = "";
129                 String description = "";
130                 foreach (XmlAttribute domAtt in domChild.Attributes)
131                 {
132                     if (domAtt.Name == "name")
133                     {
134                         name = domAtt.Value;
135                     }
136                     if (domAtt.Name == "index")
137                     {
138                         id = domAtt.Value;
139                     }
140                 }
141                 list.Add(new Img(Int16.Parse(id), name, description));
142                 if (domChild.HasChildNodes)
143                 {
144                     list.AddRange(DomtoCategory(domChild, level + 1));
145                 }
146             }
147             return list;
148         }
149 
150 
151         // Recursively called routine that displays nodes in list box
152         private ArrayList DomtoCategory(XmlNode parentNode, int level)
153         {
154             ArrayList list = new ArrayList();
155 
156             foreach (XmlNode domChild in parentNode.ChildNodes)
157             {
158                 String name = "";
159                 String id = "";
160                 foreach (XmlAttribute domAtt in domChild.Attributes)
161                 {
162                     if (domAtt.Name == "name")
163                     {
164                         name = domAtt.Value;
165                     }
166                     if (domAtt.Name == "index")
167                     {
168                         id = domAtt.Value;
169                     }
170                 }
171                 list.Add(new Category(Int16.Parse(id), name));
172                 if (domChild.HasChildNodes)
173                 {
174                     list.AddRange(DomtoCategory(domChild, level + 1));
175                 }
176             }
177             return list;
178         }
179 
180         public ArrayList getImagesList(String server, int id)
181         {
182             ArrayList lst = new ArrayList();
183             form.displayMessage("Fetching Images List");
184             currentSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
185             IPHostEntry IPHost = Dns.GetHostEntry(server);
186             IPEndPoint ipServer = new IPEndPoint(IPHost.AddressList[0].Address, PORT);
187             currentSocket.Connect(ipServer);
188 
189             String sendString = "<ReqSession>dallin</ReqSession>";
190             this.sendString(sendString);
191             String res = this.getResponse();
192             form.setResponse(res);
193             sendString = "<ImageListRequest category="" + id + ""/>";
194             this.sendString(sendString);
195             res = this.getResponse();
196             form.setResponse(res);
197             XmlDocument xml = new XmlDocument();
198             xml.LoadXml(res);
199 
200             lst.AddRange(this.DomtoImage(xml.DocumentElement, 0));
201 
202             sendString = "<Complete />";
203             this.sendString(sendString);
204             res = this.getResponse();
205             currentSocket.Disconnect(false);
206             currentSocket.Close();
207             form.displayMessage("Images List recieved");
208             return lst;
209         }
210 
211         private Bitmap FieldToImage(Byte[] imageBytes)
212         {
213             Bitmap img;
214             MemoryStream ms;
215             ms = new MemoryStream(imageBytes);
216             img = new Bitmap(ms);
217             ms.Close();
218             return img;
219         }
220 
221         private Bitmap fetch(int length)
222         {
223             byte[] buffer = new byte[length];
224             try
225             {
226                 int count = 0;
227                 while (count < length)
228                 {
229                     count += currentSocket.Receive(buffer, count, (length - count), SocketFlags.None);
230                 }
231             }
232             catch (SocketException se)
233             {
234                 return new Bitmap("G:SchoolCN3670labsImageServerImageClient1.bmp");
235             }
236             return FieldToImage(buffer);
237         }
238         //This is to be added for part two.
239         public Bitmap getImage(String server, int id)
240         {
241             Bitmap img;
242             ArrayList lst = new ArrayList();
243             form.displayMessage("Fetching Image ::" + id);
244             currentSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
245             IPHostEntry IPHost = Dns.GetHostEntry(server);
246             IPEndPoint ipServer = new IPEndPoint(IPHost.AddressList[0].Address, PORT);
247             currentSocket.Connect(ipServer);
248 
249             String sendString = "<ReqSession>dallin</ReqSession>";
250             this.sendString(sendString);
251             String res = this.getResponse();
252             form.setResponse(res);
253             sendString = "<GetImage index="" + id + ""/>";
254             this.sendString(sendString);
255             res = this.getResponse();
256             form.setResponse(res);
257             XmlDocument xml = new XmlDocument();
258             xml.LoadXml(res);
259             int length = Int32.Parse(xml.DocumentElement.Attributes["length"].Value);
260 
261             img = fetch(length);
262 
263             sendString = "<Complete />";
264             this.sendString(sendString);
265             res = this.getResponse();
266             currentSocket.Disconnect(false);
267             currentSocket.Close();
268             form.displayMessage("Image ::" + id + " recieved ("+length+" byte(s) long)");
269             return img;
270         }
271     }
272 }

And the classes that handle the information from the database (used for list objects) Img.cs:

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 
 5 namespace ImageServer
 6 {
 7     class Img
 8     {
 9         public int cId;
10         public String cName;
11         public String cDescription;
12         //public Bitmap cImage;
13 
14         public Img(int id, String name, String description/*, Bitmap img*/)
15         {
16             cId = id;
17             cName = name;
18             cDescription = description;
19             //cImage = img;
20         }
21     }
22 }

Now the Category.cs file:

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 
 5 namespace ImageServer
 6 {
 7 
 8     class Category
 9     {
10         public int cId;
11         public String cName;
12 
13         public Category(int id, String name)
14         {
15             cId = id;
16             cName = name;
17         }
18 
19         string ToString()
20         {
21             return "(" + cId + ")" + cName;
22         }
23     }
24 }

Write a program that will connect to the Image Database, list the categories from the category table then when the user selects a category in the list, show the name of all images in that category in another list box. To access the database, you will need to be logged into CSEVPN.

Form Design

• Add an Open button that will connect to the database.
• Add a Category ListBox.
• Add an Image Title ListBox.

Open Button Event Routine

• You will need to use System.Data.SqlClient name space.
• You will need to define the fillowing database objects:
  • SqlConnection connct = null;
  • SqlCommand cmd = null;
  • SqlDataReader dr = null;
• Please click here and read about the SQL select statement.
• Please read about the SqlConnection, SqlCommand and SqlDataReader in your IDE helps. You should also be able to use ODBC drivers and objects.
• You will need the following database connection string with your connection object:
  “user id=ImageDB;password=1mag3Database;data source=CNS-LOVE.csevpn.local;persist security info=False;initial catalog=ImageArchive”
  This database has two tables you will be using: Categories and Images.
• The following code will select all categories and add them to the first list box.

  connct = new SqlConnection(MY_CONNECTION_STRING);
  connct.Open();
  cmd = new SqlCommand("Select * from Categories", connct);
  dr = cmd.ExecuteReader();
  while (dr.Read())
  {
  	lstCategory.Items.Add(dr["Category"].ToString());
  }

• YOU MUST CLOSE OUT ALL DB OBJECTS WHEN YOU FINISH WITH THEM:

  if (dr != null)
  {
  	dr.Close();
  	dr.Dispose();
  	dr = null;
  }
  if (cmd != null)
  {
  	cmd.Dispose();
  	cmd = null;
  }
  if (connct != null && connct.State == ConnectionState.Open)
  {
  	connct.Close();
  	connct.Dispose();
  	connct = null;
  }

• You will need to use the MouseDoubleClick event for your selection in the Category Listbox:

  private void lstCategory_MouseDoubleClick(object sender, MouseEventArgs e)
  {
  
  }

• To get the correct image, you need to use a select with a WHERE clause:
  SELECT CIndex, Description FROM Images WHERE CIndex = n
  where n = the category number. Do not select all fields from the Image table, the picture field values are very large.
  So, where do you get a value for n? One simple solution is, when you read a category record, create an object that has the “Category” text and the “CIndex” value from the table. You can then override the ToString() method and add your new object’s reference to the category listbox items list.
• The value you will add to the image list box will be from the table field “Description&quot.

Here is a screen shot of my program actually running:

Here is a copy of my code:

FormMain.cs:
 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Text;
 7 using System.Windows.Forms;
 8 using System.Data.SqlClient;
 9 
10 namespace DatabaseConnect
11 {
12     public partial class FormMain : Form
13     {
14         SqlConnection connct = null;
15         SqlCommand cmd = null;
16         SqlDataReader dr = null;
17         String MY_CONNECTION_STRING = "Data Source=CNS-LOVE.csevpn.local;Initial Catalog=ImageArchive;Persist Security Info=True;User ID=ImageDB;Password=MyPassword";
18         System.Collections.ArrayList categories;
19 
20         public FormMain()
21         {
22             InitializeComponent();
23         }
24 
25         private void buttonOpen_Click(object sender, EventArgs e)
26         {
27             connct = new SqlConnection(MY_CONNECTION_STRING);
28             connct.Open();
29             cmd = new SqlCommand("Select * from Categories", connct);
30             dr = cmd.ExecuteReader();
31             categories = new System.Collections.ArrayList();
32             while (dr.Read())
33             {
34                 categories.Add(new Category(dr["Category"].ToString(), Int16.Parse(dr["CIndex"].ToString())));
35                 listCategories.Items.Add(dr["Category"].ToString());
36             }
37             if (dr != null)
38             {
39                 dr.Close();
40                 dr.Dispose();
41                 dr = null;
42             }
43             if (cmd != null)
44             {
45                 cmd.Dispose();
46                 cmd = null;
47             }
48             if (connct != null && connct.State == ConnectionState.Open)
49             {
50                 connct.Close();
51                 connct.Dispose();
52                 connct = null;
53             }
54         }
55 
56         private void listCategories_DoubleClick(object sender, EventArgs e)
57         {
58             listImages.Items.Clear();
59             connct = new SqlConnection(MY_CONNECTION_STRING);
60             connct.Open();
61             cmd = new SqlCommand("Select * from Images WHERE cIndex =@n", connct);
62             cmd.Parameters.AddWithValue("@n", ((Category)(categories[listCategories.SelectedIndex])).getId());
63             dr = cmd.ExecuteReader();
64             while (dr.Read())
65             {
66                 listImages.Items.Add(dr["FileName"].ToString());
67             }
68             if (dr != null)
69             {
70                 dr.Close();
71                 dr.Dispose();
72                 dr = null;
73             }
74             if (cmd != null)
75             {
77                 cmd.Dispose();
77                 cmd = null;
78             }
79             if (connct != null && connct.State == ConnectionState.Open)
80             {
81                 connct.Close();
82                 connct.Dispose();
83                 connct = null;
84             }
85         }
86 
87     }
88 }

Category.cs
 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 
 5 namespace DatabaseConnect
 6 {
 7     class Category
 8     {
 9         private String name;
10         private Int16 id;
11 
12         public Category(String n, Int16 i)
13         {
14             name = n;
15             id = i;
16         }
17 
18         public String getName()
19         {
20             return name;
21         }
22 
23         public Int16 getId()
24         {
25             return id;
26         }
27     }
28 }

  1 using System;

  2 using System.Collections.Generic;

  3 using System.ComponentModel;

  4 using System.Data;

  5 using System.Drawing;

  6 using System.Text;

  7 using System.Windows.Forms;

  8 using System.Net;

  9 using System.Net.Sockets;

 10 using System.Threading;

 11 

 12 namespace MultiCastChat

 13 {

 14     public partial class formMain : Form

 15     {

 16         private const int TIME_TO_LIVE = 50;

 17         private UdpClient client = null;

 18         private IPAddress group = null;

 19         private int port = 0;

 20         private IPEndPoint multiCastEP = null;

 21 

 22         private bool stayAlive = true;

 23         private Thread receiveThread = null;

 24         private string defaultNameText = "";

 25 

 26         public delegate void dListOngoing(string message);

 27         public dListOngoing listOngoing;

 28 

 29         public formMain()

 30         {

 31             InitializeComponent();

 32         }

 33 

 34         private void formMain_Load(object sender, EventArgs e)

 35         {

 36             comboAddress.SelectedIndex = 0;

 37             defaultNameText = textboxName.Text;

 38             this.AcceptButton = buttonJoin;

 39             this.CancelButton = buttonExit;

 40             this.buttonJoin.Enabled = true;

 41             this.buttonExit.Enabled = true;

 42             this.buttonSend.Enabled = true;

 43             this.textboxPort.Text = "" + 10002;

 44             textboxInput.Focus();

 45             listOngoing = new dListOngoing(displayMessage);

 46         }

 47 

 48         private void buttonSend_Click(object sender, EventArgs e)

 49         {

 50             this.SendMessage(textboxInput.Text);

 51         }

 52 

 53         private void buttonEnd_Click(object sender, EventArgs e)

 54         {

 55             this.LeaveGroup();

 56 

 57             buttonJoin.Enabled = true;

 58             buttonEnd.Enabled = false;

 59             buttonSend.Enabled = false;

 60             this.AcceptButton = buttonJoin;

 61             this.CancelButton = buttonExit;

 62         }

 63 

 64         private void SendMessage(String message)

 65         {

 66             Byte[] buff;

 67 

 68             buff = Encoding.ASCII.GetBytes(textboxName.Text + ": " + message);

 69             client.Send(buff, buff.Length, multiCastEP);

 70             textboxInput.Text = "";

 71         }

 72 

 73         private void LeaveGroup()

 74         {

 75             if (group != null)

 76             {

 77                 SendMessage("Leaving Chat");

 78                 Application.DoEvents();

 79                 Thread.Sleep(500);

 80                 stayAlive = false;

 81                 while (receiveThread.IsAlive) Application.DoEvents();

 82                 receiveThread.Join();

 83                 client.DropMulticastGroup(group);

 84                 client.Close();

 85                 client = null;

 86                 group = null;

 87                 multiCastEP = null;

 88             }

 89         }

 90 

 91         private void JoinGroup()

 92         {

 93             if (!int.TryParse(textboxPort.Text, out port))

 94                 throw new ApplicationException("Invalid Port Number");

 95             if (!IPAddress.TryParse(comboAddress.Text, out group))

 96                 throw new ApplicationException("Invalid Multicast Group Address");

 97 

 98             client = new UdpClient(port);

 99             client.JoinMulticastGroup(group, TIME_TO_LIVE);

100             multiCastEP = new IPEndPoint(group, port);

101 

102             this.stayAlive = true;

103             receiveThread = new Thread(this.runThread);

104             receiveThread.Start();

105 

106             this.SendMessage("has joined the chat!");

107             this.AcceptButton = buttonSend;

108             this.CancelButton = buttonEnd;

109             this.buttonJoin.Enabled = false;

110             this.buttonEnd.Enabled = true;

111             this.buttonSend.Enabled = true;

112             textboxInput.Focus();

113         }

114 

115         private void runThread()

116         {

117             Byte[] buff;

118             String message;

119             while (stayAlive)

120             {

121                 IPEndPoint ep = null;

122                 if (client.Available > 0)

123                 {

124                     buff = client.Receive(ref ep);

125                     message = Encoding.ASCII.GetString(buff);

126                     this.Invoke(this.listOngoing, message);

127                 }

128                 else

129                 {

130                     Thread.Sleep(10);

131                 }

132             }

133         }

134 

135         private void buttonExit_Click(object sender, EventArgs e)

136         {

137             this.LeaveGroup();

138             buttonJoin.Enabled = true;

139             buttonEnd.Enabled = false;

140             buttonSend.Enabled = false;

141             this.AcceptButton = buttonJoin;

142             this.CancelButton = buttonExit;

143             this.Close();

144         }

145 

146         public void displayMessage(string message)

147         {

148             lstOngoing.Items.Add(message);

149             lstOngoing.Refresh();

150         }

151 

152         private void buttonJoin_Click(object sender, EventArgs e)

153         {

154             this.JoinGroup();

155         }

156     }

157 }

Here is a screen shot of my application connected to another member of the class.

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Text;
 4 
 5 namespace Names
 6 {
 7     class Program
 8     {
 9         static void Main(string[] args)
10         {
11             String firstName;
12             String lastName;
13             String fullName;
14 
15             System.Console.Write("Please enter your first name: ");
16             firstName = System.Console.ReadLine();
17 
18             System.Console.Write("Please enter your last name: ");
19             lastName = System.Console.ReadLine();
20 
21             fullName = firstName + " " + lastName;
22             System.Console.WriteLine("your name (first last) is: " + fullName);
23 
24             fullName = lastName + ", " + firstName;
25             System.Console.WriteLine("your name (last, first) is: " + fullName);
26 
27             System.Console.ReadLine();
28         }
29     }
30 }