C#入门代码

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:    emp    est.txt         FileStream fs = new FileStream( @c:    emp    est.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:    emp    est.txt         FileStream fs = new FileStream( @c:    emp    est.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(
        {
            0
        }
        , DateTime.Now );
    }
}
七、调用外部程序：class Test
{
    static void Main( string[] args )    
    {
        System.Diagnostics.Process.Start( notepad.exe );
    }
}
ADO.NET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:    est.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:
            {
                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:    est.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:    est.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方面的十四、一个ASP.NET程序：<%@ Page Language=C# %><script runat=server>       void Button1_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=Button1_Click runat=server Text=Submit></asp:Button>        </p>    </form></body></html>WinForm开发：十五、一个简单的WinForm程序：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( ) );
    }
}
十六、运行时显示自己定义的图标：//load icon and set to formSystem.Drawing.Icon ico = new System.Drawing.Icon( @c:    empapp.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 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.ToString ( ) );
        }
    }
}
十九、取得机器名称：using System;
using System.Net;
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@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( ) );
        }
    }
}
二十一、根据IP地址得出机器名称：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+方面的：二十二、GDI+入门介绍：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 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: + 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( ) );
        }
    }
}
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.;
    }
}