C#入門代碼

編輯：關於C語言

一、從控制台讀取東西代碼片斷：
using System;

class TestReadConsole
{
public static void Main()
{
      Console.Write(Enter your name:);
      string strName = Console.ReadLine();
      Console.WriteLine( Hi + strName);
}
}
二、讀文件代碼片斷：
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、寫文件代碼：
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、拷貝文件：
using System;
using System.IO;

class TestCopyFile
{
public static void Main()
{
      File.Copy(c:\\temp\\source.txt, C:\\temp\\dest.txt );
}
}
五、移動文件：
using System;
using System.IO;

class TestMoveFile
{
public static void Main()
{
      File.Move(c:\\temp\\abc.txt, C:\\temp\\def.txt );
}
}
六、使用計時器：
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、調用外部程序：
class Test
{
static void Main(string[] args)
{
      System.Diagnostics.Process.Start(notepad.exe);
}
}

ADO.Net方面的：
八、連接Access數據庫：
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、連接SQL Server數據庫：
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、從SQL內讀數據到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添加數據到數據庫中：
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連接數據庫：
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、讀取表的屬性：
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、一個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開發：
十五、一個簡單的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、運行時顯示自己定義的圖標：
//load icon and set to form
System.Drawing.Icon ico = new System.Drawing.Icon(@c:\temp\app.ico);
this.Icon = ico;
十七、添加組件到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);
}

網絡方面的：
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、取得機器名稱：
using System;
using System.Net;

class GetIP
{
public static void Main()
{
      Console.WriteLine (Host name : {0}, Dns.GetHostName());
}
}
二十、發送郵件：
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 = [email protected];
         message.To =  [email protected];
         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、根據IP地址得出機器名稱：
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+入門介紹：
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、讀取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、寫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、一個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.;
}
}