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:/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(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 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：
  <% @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.;
   }
  }
  
  
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