C#入门代码,csharp

一、从控制台读取东西代码片断：

using System;

class TestReadConsole

{

public static void Main()

{

Console.Write(Enter your name:);

string strName = Console.ReadLine();

Console.WriteLine( Hi + strName);

}

}

二、读文件代码片断：

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();

}

}

三、写文件代码：

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();

}

}

四、拷贝文件：

using System;

using System.IO;

class TestCopyFile

{

public static void Main()

{

File.Copy(c:\\temp\\source.txt, C:\\temp\\dest.txt );

}

}

五、移动文件：

using System;

using System.IO;

class TestMoveFile

{

public static void Main()

{

File.Move(c:\\temp\\abc.txt, C:\\temp\\def.txt );

}

}

六、使用计时器：

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);

}

}

七、调用外部程序：

class Test

{

static void Main(string[] args)

{

System.Diagnostics.Process.Start(notepad.exe);

}

}

https://www.360docs.net/doc/7317467181.html,方面的：

八、连接Access数据库：

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();

}

}

}

九、连接SQL Server数据库：

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);

}

}

}

十、从SQL内读数据到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();

}

}

十一、用ADO添加数据到数据库中：

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();

}

}

}

十二、使用OLEConn连接数据库：

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();

}

}

十三、读取表的属性：

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();

}

}

https://www.360docs.net/doc/7317467181.html,方面的

十四、一个https://www.360docs.net/doc/7317467181.html,程序：

<%@ Page Language=C# %>

Enter your name:

runat=server>

Width=247px>

WinForm开发：

十五、一个简单的WinForm程序：

using System;

using System.Drawing;

using System.Collections;

using https://www.360docs.net/doc/7317467181.html,ponentModel;

using System.Windows.Forms;

using System.Data;

public class SimpleForm : System.Windows.Forms.Form

{

private https://www.360docs.net/doc/7317467181.html,ponentModel.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()

{

https://www.360docs.net/doc/7317467181.html,ponents = new https://www.360docs.net/doc/7317467181.html,ponentModel.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);

https://www.360docs.net/doc/7317467181.html, = 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);

https://www.360docs.net/doc/7317467181.html, = 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});

https://www.360docs.net/doc/7317467181.html, = Form1;

this.Text = Form1;

this.ResumeLayout(false);

}

#endregion

[STAThread]

static void Main()

{

Application.Run(new SimpleForm());

}

}

十六、运行时显示自己定义的图标：

//load icon and set to form

System.Drawing.Icon ico = new System.Drawing.Icon(@c:\temp\app.ico); this.Icon = ico;

十七、添加组件到ListBox中：

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);

}

网络方面的：

十八、取得IP地址：

using System;

using https://www.360docs.net/doc/7317467181.html,;

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.ToString ());

}

}

}

十九、取得机器名称：

using System;

using https://www.360docs.net/doc/7317467181.html,;

class GetIP

{

public static void Main()

{

Console.WriteLine (Host name : {0}, Dns.GetHostName()); }

}

二十、发送邮件：

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@https://www.360docs.net/doc/7317467181.html,;

message.To = pengyun@https://www.360docs.net/doc/7317467181.html,;

https://www.360docs.net/doc/7317467181.html, = ;

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());

}

}

}

二十一、根据IP地址得出机器名称：

using System;

using https://www.360docs.net/doc/7317467181.html,;

class ResolveIP

{

public static void Main()

{

IPHostEntry ipEntry = Dns.Resolve(172.29.9.9);

Console.WriteLine (Host name : {0},

ipEntry.HostName);

}

}

GDI+方面的：

二十二、GDI+入门介绍：

using System;

using System.Drawing;

using System.Collections;

using https://www.360docs.net/doc/7317467181.html,ponentModel;

using System.Windows.Forms;

using System.Data;

public class Form1 : System.Windows.Forms.Form

{

private https://www.360docs.net/doc/7317467181.html,ponentModel.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);

https://www.360docs.net/doc/7317467181.html, = 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 Form1_Paint(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),10,10,200,100);

g.DrawEllipse(new Pen(Color.Yellow),10,150,200,100);

}

}

XML方面的：

二十三、读取XML文件：

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: + https://www.360docs.net/doc/7317467181.html,);

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());

}

}

}

二十四、写XML文件：

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方面的：

二十五、一个Web Service的小例子：

<% @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.; }

}