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=lo