General little things:
1. Read the code snippet from the console:
Using System;
Class TestReadConsole
{
Public static void Main ()
{
Console. Write ("Enter your name :");
String strName = Console. ReadLine ();
Console. WriteLine ("Hi" + strName );
}
}
Ii. Read File code snippets:
Using System;
Using System. IO;
Public class TestReadFile
{
Public static void Main (String [] args)
{
// Read text file C:/temp/test.txt
FileStream fs = new FileStream (@ "c:/temp/test.txt", FileMode. Open, FileAccess. Read );
StreamReader sr = new StreamReader (fs );
String line = sr. ReadLine ();
While (line! = Null)
{
Console. WriteLine (line );
Line = sr. ReadLine ();
}
Sr. Close ();
Fs. Close ();
}
}
3. Write File Code:
Using System;
Using System. IO;
Public class TestWriteFile
{
Public static void Main (String [] args)
{
// Create a text file C:/temp/test.txt
FileStream fs = new FileStream (@ "c:/temp/test.txt", FileMode. OpenOrCreate, FileAccess. Write );
StreamWriter sw = new StreamWriter (fs );
// Write to the file using StreamWriter class
Sw. BaseStream. Seek (0, SeekOrigin. End );
Sw. WriteLine ("First Line ");
Sw. WriteLine ("Second Line ");
Sw. Flush ();
}
}
4. Copy an object:
Using System;
Using System. IO;
Class TestCopyFile
{
Public static void Main ()
{
File. Copy ("c: // temp // source.txt", "C: // temp ///dest.txt ");
}
}
5. Move files:
Using System;
Using System. IO;
Class TestMoveFile
{
Public static void Main ()
{
File. Move ("c: // temp // abc.txt", "C: // temp ///def.txt ");
}
}
6. Use a Timer:
Using System;
Using System. Timers;
Class TestTimer
{
Public static void Main ()
{
Timer timer = new Timer ();
Timer. Elapsed + = new ElapsedEventHandler (DisplayTimeEvent );
Timer. Interval = 1000;
Timer. Start ();
Timer. Enabled = true;
While (Console. Read ()! = 'Q ')
{
}
}
Public static void DisplayTimeEvent (object source, ElapsedEventArgs e)
{
Console. Write ("/r {0}", DateTime. Now );
}
}
7. Call external programs:
Class Test
{
Static void Main (string [] args)
{
System. Diagnostics. Process. Start ("notepad.exe ");
}
}
ADO. NET:
8. Access database connection:
Using System;
Using System. Data;
Using System. Data. OleDb;
Class TestADO
{
Static void Main (string [] args)
{
String strDSN = "Provider = Microsoft. Jet. OLEDB.4.0; Data Source = c: // test. mdb ";
String strSQL = "SELECT * FROM employees ";
OleDbConnection conn = new OleDbConnection (strDSN );
OleDbCommand cmd = new OleDbCommand (strSQL, conn );
OleDbDataReader reader = null;
Try
{
Conn. Open ();
Reader = cmd. ExecuteReader ();
While (reader. Read ())
{
Console. WriteLine ("First Name: {0}, Last Name: {1}", reader ["FirstName"], reader ["LastName"]);
}
}
Catch (Exception e)
{
Console. WriteLine (e. Message );
}
Finally
{
Conn. Close ();
}
}
}
9. Connect to the SQL Server database:
Using System;
Using System. Data. SqlClient;
Public class TestADO
{
Public static void Main ()
{
SqlConnection conn = new SqlConnection ("Data Source = localhost; Integrated Security = SSPI; Initial Catalog = pubs ");
SqlCommand cmd = new SqlCommand ("SELECT * FROM employees", conn );
Try
{
Conn. Open ();
SqlDataReader reader = cmd. ExecuteReader ();
While (reader. Read ())
{
Console. WriteLine ("First Name: {0}, Last Name: {1}", reader. GetString (0), reader. GetString (1 ));
}
Reader. Close ();
Conn. Close ();
}
Catch (Exception e)
{
Console. WriteLine ("Exception Occured --> {0}", e );
}
}
}
10. read data from SQL to XML:
Using System;
Using System. Data;
Using System. Xml;
Using System. Data. SqlClient;
Using System. IO;
Public class TestWriteXML
{
Public static void Main ()
{
String strFileName = "c:/temp/output. xml ";
SqlConnection conn = new SqlConnection ("server = localhost; uid = sa; pwd =; database = db ");
String strSql = "SELECT FirstName, LastName FROM employees ";
SqlDataAdapter adapter = new SqlDataAdapter ();
Adapter. SelectCommand = new SqlCommand (strSql, conn );
// Build the DataSet
DataSet ds = new DataSet ();
Adapter. Fill (ds, "employees ");
// Get a FileStream object
FileStream fs = new FileStream (strFileName, FileMode. OpenOrCreate, FileAccess. Write );
// Apply the WriteXml method to write an XML document
Ds. WriteXml (fs );
Fs. Close ();
}
}
11. add data to the database using ADO:
Using System;
Using System. Data;
Using System. Data. OleDb;
Class TestADO
{
Static void Main (string [] args)
{
String strDSN = "Provider = Microsoft. Jet. OLEDB.4.0; DataSource = c:/test. mdb ";
String strSQL = "insert into Employee (FirstName, LastName) VALUES ('firstname', 'lastname ')";
// Create Objects of ADOConnection and ADOCommand
OleDbConnection conn = new OleDbConnection (strDSN );
OleDbCommand cmd = new OleDbCommand (strSQL, conn );
Try
{
Conn. Open ();
Cmd. ExecuteNonQuery ();
}
Catch (Exception e)
{
Console. WriteLine ("Oooops. I did it again:/n {0}", e. Message );
}
Finally
{
Conn. Close ();
}
}
}
12. Use OLEConn to connect to the database:
Using System;
Using System. Data;
Using System. Data. OleDb;
Class TestADO
{
Static void Main (string [] args)
{
String strDSN = "Provider = Microsoft. Jet. OLEDB.4.0; DataSource = c:/test. mdb ";
String strSQL = "SELECT * FROM employee ";
OleDbConnection conn = new OleDbConnection (strDSN );
OleDbDataAdapter cmd = new OleDbDataAdapter (strSQL, conn );
Conn. Open ();
DataSet ds = new DataSet ();
Cmd. Fill (ds, "employee ");
DataTable dt = ds. Tables [0];
Foreach (DataRow dr in dt. Rows)
{
Console. WriteLine ("First name:" + dr ["FirstName"]. ToString () + "Last name:" + dr ["LastName"]. ToString ());
}
Conn. Close ();
}
}
13. Read table attributes:
Using System;
Using System. Data;
Using System. Data. OleDb;
Class TestADO
{
Static void Main (string [] args)
{
String strDSN = "Provider = Microsoft. Jet. OLEDB.4.0; DataSource = c:/test. mdb ";
String strSQL = "SELECT * FROM employee ";
OleDbConnection conn = new OleDbConnection (strDSN );
OleDbDataAdapter cmd = new OleDbDataAdapter (strSQL, conn );
Conn. Open ();
DataSet ds = new DataSet ();
Cmd. Fill (ds, "employee ");
DataTable dt = ds. Tables [0];
Console. WriteLine ("Field Name DataType Unique AutoIncrement AllowNull ");
Console. writeLine ("========================================== =============================== ");
Foreach (DataColumn dc in dt. Columns)
{
Console. writeLine (dc. columnName + "," + dc. dataType + "," + dc. unique + "," + dc. autoIncrement + "," + dc. allowDBNull );
}
Conn. Close ();
}
}
ASP. NET
14. An ASP. NET program:
<% @ Page Language = "C #" %>
<Script runat = "server">
Void button#click (Object sender, EventArgs e)
{
Label1.Text = TextBox1.Text;
}
</Script>
<Html>
<Head>
</Head>
<Body>
<Form runat = "server">
<P>
<Br/>
Enter your name: <asp: TextBox id = "TextBox1" runat = "server"> </asp: TextBox>
</P>
<P>
<B> <asp: Label id = "Label1" runat = "server" Width = "247px"> </asp: Label> </B>
</P>
<P>
<Asp: Button id = "Button1" onclick = "button#click" runat = "server" Text = "Submit"> </asp: Button>
</P>
</Form>
</Body>
</Html>
WinForm development:
15. A simple WinForm program:
Using System;
Using System. Drawing;
Using System. Collections;
Using System. ComponentModel;
Using System. Windows. Forms;
Using System. Data;
Public class SimpleForm: System. Windows. Forms. Form
{
Private System. ComponentModel. Container components = null;
Private System. Windows. Forms. Button button1;
Private System. Windows. Forms. TextBox textBox1;
Public SimpleForm ()
{
InitializeComponent ();
}
Protected override void Dispose (bool disposing)
{
If (disposing)
{
If (components! = Null)
{
Components. Dispose ();
}
}
Base. Dispose (disposing );
}
# Region Windows Form Designer generated code
Private void InitializeComponent ()
{
This. components = new System. ComponentModel. Container ();
This. Size = new System. Drawing. Size (300,300 );
This. Text = "Form1 ";
This. button1 = new System. Windows. Forms. Button ();
This. textBox1 = new System. Windows. Forms. TextBox ();
This. SuspendLayout ();
//
// Button1
//
This. button1.Location = new System. Drawing. Point (8, 16 );
This. button1.Name = "button1 ";
This. button1.Size = new System. Drawing. Size (80, 24 );
This. button1.TabIndex = 0;
This. button1.Text = "button1 ";
//
// TextBox1
//
This. textBox1.Location = new System. Drawing. Point (112, 16 );
This. textBox1.Name = "textBox1 ";
This. textBox1.Size = new System. Drawing. Size (160, 20 );
This. textBox1.TabIndex = 1;
This. textBox1.Text = "textBox1 ";
//
// Form1
//
This. AutoScaleBaseSize = new System. Drawing. Size (5, 13 );
This. ClientSize = new System. Drawing. Size (292,273 );
This. Controls. AddRange (new System. Windows. Forms. Control [] {
This. textBox1,
This. button1 });
This. Name = "Form1 ";
This. Text = "Form1 ";
This. ResumeLayout (false );
}
# Endregion
[STAThread]
Static void Main ()
{
Application. Run (new SimpleForm ());
}
}
16. display the custom icon during running:
// Load icon and set to form
System. Drawing. Icon ico = new System. Drawing. Icon (@ "c:/temp/app. ico ");
This. Icon = ico;
17. Add the component to ListBox:
Private void Form1_Load (object sender, System. EventArgs e)
{
String str = "First item ";
Int I = 23;
Float flt = 34.98f;
ListBox1.Items. Add (str );
ListBox1.Items. Add (I. ToString ());
ListBox1.Items. Add (flt. ToString ());
ListBox1.Items. Add ("Last Item in the List Box ");
}
Network:
18. Obtain the IP Address:
Using System;
Using System. Net;
Class GetIP
{
Public static void Main ()
{
IPHostEntry ipEntry = Dns. GetHostByName ("localhost ");
IPAddress [] IpAddr = ipEntry. AddressList;
For (int I = 0; I <IpAddr. Length; I ++)
{
Console. WriteLine ("IP Address {0 }:{ 1}", I, IpAddr [I]. ToString ());
}
}
}
19. Obtain the machine Name:
Using System;
Using System. Net;
Class GetIP
{
Public static void Main ()
{
Console. WriteLine ("Host name: {0}", Dns. GetHostName ());
}
}
20. send an email:
Using System;
Using System. Web;
Using System. Web. Mail;
Public class TestSendMail
{
Public static void Main ()
{
Try
{
// Construct a new mail message
MailMessage message = new MailMessage ();
Message. From = "from@domain.com ";
Message. To = "pengyun@cobainsoft.com ";
Message. Cc = "";
Message. Bcc = "";
Message. Subject = "Subject ";
Message. Body = "Content of message ";
// If you want attach file with this mail, add the line below
Message. Attachments. Add (new MailAttachment ("c: // attach.txt", MailEncoding. Base64 ));
// Send the message
SmtpMail. Send (message );
System. Console. WriteLine ("Message has been sent ");
}
Catch (Exception ex)
{
System. Console. WriteLine (ex. Message. ToString ());
}
}
}
21. Obtain the machine name based on the IP Address:
Using System;
Using System. Net;
Class ResolveIP
{
Public static void Main ()
{
IPHostEntry ipEntry = Dns. Resolve ("172.29.9.9 ");
Console. WriteLine ("Host name: {0}", ipEntry. HostName );
}
}
GDI +:
22. Introduction to GDI +:
Using System;
Using System. Drawing;
Using System. Collections;
Using System. ComponentModel;
Using System. Windows. Forms;
Using System. Data;
Public class Form1: System. Windows. Forms. Form
{
Private System. ComponentModel. Container components = null;
Public Form1 ()
{
InitializeComponent ();
}
Protected override void Dispose (bool disposing)
{
If (disposing)
{
If (components! = Null)
{
Components. Dispose ();
}
}
Base. Dispose (disposing );
}
# Region Windows Form Designer generated code
Private void InitializeComponent ()
{
This. AutoScaleBaseSize = new System. Drawing. Size (5, 13 );
This. ClientSize = new System. Drawing. Size (292,273 );
This. Name = "Form1 ";
This. Text = "Form1 ";
This. Paint + = new System. Windows. Forms. PaintEventHandler (this. Form1_Paint );
}
# Endregion
[STAThread]
Static void Main ()
{
Application. Run (new Form1 ());
}
Private void formatepaint (object sender, System. Windows. Forms. PaintEventArgs e)
{
Graphics g = e. Graphics;
G. DrawLine (new Pen (Color. Blue), 10, 10, 210,110 );
G. DrawRectangle (new Pen (Color. Red), 200,100 );
G. DrawEllipse (new Pen (Color. Yellow), 10,150,200,100 );
}
}
XML:
23. Read XML files:
Using System;
Using System. Xml;
Class TestReadXML
{
Public static void Main ()
{
XmlTextReader reader = new XmlTextReader ("C: // test. xml ");
Reader. Read ();
While (reader. Read ())
{
Reader. MoveToElement ();
Console. WriteLine ("XmlTextReader Properties Test ");
Console. WriteLine ("========================= ");
// Read this properties of element and display them on console
Console. WriteLine ("Name:" + reader. Name );
Console. WriteLine ("Base URI:" + reader. BaseURI );
Console. WriteLine ("Local Name:" + reader. LocalName );
Console. WriteLine ("Attribute Count:" + reader. AttributeCount. ToString ());
Console. WriteLine ("Depth:" + reader. Depth. ToString ());
Console. WriteLine ("Line Number:" + reader. LineNumber. ToString ());
Console. WriteLine ("Node Type:" + reader. NodeType. ToString ());
Console. WriteLine ("Attribute Count:" + reader. Value. ToString ());
}
}
}
24. Write an XML file:
Using System;
Using System. Xml;
Public class TestWriteXMLFile
{
Public static int Main (string [] args)
{
Try
{
// Creates an XML file is not exist
XmlTextWriter writer = new XmlTextWriter ("C: // temp // xmltest. xml", null );
// Starts a new document
Writer. WriteStartDocument ();
// Write comments
Writer. WriteComment ("Commentss: XmlWriter Test Program ");
Writer. WriteProcessingInstruction ("Instruction", "Person Record ");
// Add elements to the file
Writer. WriteStartElement ("p", "person", "urn: person ");
Writer. WriteStartElement ("LastName ","");
Writer. WriteString ("Chand ");
Writer. WriteEndElement ();
Writer. WriteStartElement ("FirstName ","");
Writer. WriteString ("Mahesh ");
Writer. WriteEndElement ();
Writer. WriteElementInt16 ("age", "", 25 );
// Ends the document
Writer. WriteEndDocument ();
}
Catch (Exception e)
{
Console. WriteLine ("Exception: {0}", e. ToString ());
}
Return 0;
}
}
Web Service:
25. A small example of a Web Service:
<% @ WebService Language = "C #" Class = "TestWS" %>
Using System. Web. Services;
Public class TestWS: System. Web. Services. WebService
{
[WebMethod ()]
Public string StringFromWebService ()
{
Return "This is a string from web service .";
}
}
