• 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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  • 原文地址:https://www.cnblogs.com/AloneSword/p/2237637.html
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