C#入门代码集

    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");
    }
    }
    
    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:\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();
    }
    }
    
    ASP.NET方面的
    十四、一个ASP.NET程序：
    
    <%@Page Language="C#" %><script runat="server"> void Button1_Click(Objectsender, EventArgs e){Label1.Text=TextBox1.Text;} </script> <html> <head> </head> <body> <form runat="server"> <p> <br /> Enteryour 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 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 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：
    
    
    using System.Web.Services;
    
    public class TestWS : System.Web.Services.WebService
    {
    [WebMethod()]
    public string StringFromWebService()
    {
    return "This is a string from web service.";
    }
    }