C#常用代码
1、http://www.cnblogs.com/me-sa/articles/548636.html
一、从控制台读取东西代码片断： 4using System; 5 6class TestReadConsole 7{ 8 public static void Main() 9 { 10 Console.Write(Enter your name:); 11 string strName = Console.ReadLine(); 12 Console.WriteLine( Hi + strName); 13 } 14} 15二、读文件代码片断： 16using System; 17using System.IO; 18 19public class TestReadFile 20{ 21 public static void Main(String[] args) 22 { 23 // Read text file C:\temp\test.txt 24 FileStream fs = new FileStream(@c:\temp\test.txt , FileMode.Open, FileAccess.Read); 25 StreamReader sr = new StreamReader(fs); 26 27 String line=sr.ReadLine(); 28 while (line!=null) 29 { 30 Console.WriteLine(line); 31 line=sr.ReadLine(); 32 } 33 34 sr.Close(); 35 fs.Close(); 36 } 37} 38三、写文件代码： 39using System; 40using System.IO; 41 42public class TestWriteFile 43{ 44 public static void Main(String[] args) 45 { 46 // Create a text file C:\temp\test.txt 47 FileStream fs = new FileStream(@c:\temp\test.txt , FileMode.OpenOrCreate, FileAccess.Write); 48 StreamWriter sw = new StreamWriter(fs); 49 // Write to the file using StreamWriter class 50 sw.BaseStream.Seek(0, SeekOrigin.End); 51 sw.WriteLine( First Line ); 52 sw.WriteLine( Second Line); 53 sw.Flush(); 54 } 55} 56四、拷贝文件： 57using System; 58using System.IO; 59 60class TestCopyFile 61{ 62 public static void Main() 63 { 64 File.Copy(c:\\temp\\source.txt, C:\\temp\\dest.txt ); 65 } 66} 67五、移动文件： 68using System; 69using System.IO; 70 71class TestMoveFile 72{ 73 public static void Main() 74 { 75 File.Move(c:\\temp\\abc.txt, C:\\temp\\def.txt ); 76 } 77} 78六、使用计时器： 79using System; 80using System.Timers; 81 82class TestTimer 83{ 84 public static void Main() 85 { 86 Timer timer = new Timer(); 87 timer.Elapsed += new ElapsedEventHandler( DisplayTimeEvent ); 88 timer.Interval = 1000; 89 timer.Start(); 90 timer.Enabled = true; 91 92 while ( Console.Read() != 'q' ) 93 { 94 95 } 96 } 97 98 public static void DisplayTimeEvent( object source, ElapsedEventArgs e ) 99 { 100 Console.Write(\r{0}, DateTime.Now); 101 } 102} 103七、调用外部程序： 104class Test 105{ 106 static void Main(string[] args) 107 { 108 System.Diagnostics.Process.Start(notepad.exe); 109 } 110} 111 112ADO.NET方面的： 113八、连接Access数据库： 114using System; 115using System.Data; 116using System.Data.OleDb; 117 118class TestADO 119{ 120 static void Main(string[] args) 121 { 122 string strDSN = Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\\test.mdb; 123 string strSQL = SELECT * FROM employees ; 124 125 OleDbConnection conn = new OleDbConnection(strDSN); 126 OleDbCommand cmd = new OleDbCommand( strSQL, conn ); 127 OleDbDataReader reader = null; 128 try 129 { 130 conn.Open(); 131 reader = cmd.ExecuteReader(); 132 while (reader.Read() ) 133 { 134 Console.WriteLine(First Name:{0}, Last Name:{1}, reader[FirstName], reader[LastName]); 135 } 136 } 137 catch (Exception e) 138 { 139 Console.WriteLine(e.Message); 140 } 141 finally 142 { 143 conn.Close(); 144 } 145 } 146} 147九、连接SQL Server数据库： 148using System; 149using System.Data.SqlClient; 150 151public class TestADO 152{ 153 public static void Main() 154 { 155 SqlConnection conn = new SqlConnection(Data Source=localhost; Integrated Security=SSPI; Initial Catalog=pubs); 156 SqlCommand cmd = new SqlCommand(SELECT * FROM employees, conn); 157 try 158 { 159 conn.Open(); 160 161 SqlDataReader reader = cmd.ExecuteReader(); 162 while (reader.Read()) 163 { 164 Console.WriteLine(First Name: {0}, Last Name: {1}, reader.GetString(0), reader.GetString(1)); 165 } 166 167 reader.Close(); 168 conn.Close(); 169 } 170 catch(Exception e) 171 { 172 Console.WriteLine(Exception Occured -->> {0},e); 173 } 174 } 175} 176十、从SQL内读数据到XML： 177using System; 178using System.Data; 179using System.Xml; 180using System.Data.SqlClient; 181using System.IO; 182 183public class TestWriteXML 184{ 185 public static void Main() 186 { 187 188 String strFileName=c:/temp/output.xml; 189 190 SqlConnection conn = new SqlConnection(server=localhost;uid=sa;pwd=;database=db); 191 192 String strSql = SELECT FirstName, LastName FROM employees; 193 194 SqlDataAdapter adapter = new SqlDataAdapter(); 195 196 adapter.SelectCommand = new SqlCommand(strSql,conn); 197 198 // Build the DataSet 199 DataSet ds = new DataSet(); 200 201 adapter.Fill(ds, employees); 202 203 // Get a FileStream object 204 FileStream fs = new FileStream(strFileName,FileMode.OpenOrCreate,FileAccess.Write); 205 206 // Apply the WriteXml method to write an XML document 207 ds.WriteXml(fs); 208 209 fs.Close(); 210 211 } 212} 213十一、用ADO添加数据到数据库中： 214using System; 215using System.Data; 216using System.Data.OleDb; 217 218class TestADO 219{ 220 static void Main(string[] args) 221 { 222 string strDSN = Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\test.mdb; 223 string strSQL = INSERT INTO Employee(FirstName, LastName) VALUES('FirstName', 'LastName') ; 224 225 // create Objects of ADOConnection and ADOCommand 226 OleDbConnection conn = new OleDbConnection(strDSN); 227 OleDbCommand cmd = new OleDbCommand( strSQL, conn ); 228 try 229 { 230 conn.Open(); 231 cmd.ExecuteNonQuery(); 232 } 233 catch (Exception e) 234 { 235 Console.WriteLine(Oooops. I did it again:\n{0}, e.Message); 236 } 237 finally 238 { 239 conn.Close(); 240 } 241 } 242} 243十二、使用OLEConn连接数据库： 244using System; 245using System.Data; 246using System.Data.OleDb; 247 248class TestADO 249{ 250 static void Main(string[] args) 251 { 252 string strDSN = Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\test.mdb; 253 string strSQL = SELECT * FROM employee ; 254 255 OleDbConnection conn = new OleDbConnection(strDSN); 256 OleDbDataAdapter cmd = new OleDbDataAdapter( strSQL, conn ); 257 258 conn.Open(); 259 DataSet ds = new DataSet(); 260 cmd.Fill( ds, employee ); 261 DataTable dt = ds.Tables[0]; 262 263 foreach( DataRow dr in dt.Rows ) 264 { 265 Console.WriteLine(First name: + dr[FirstName].ToString() + Last name: + dr[LastName].ToString()); 266 } 267 conn.Close(); 268 } 269} 270十三、读取表的属性： 271using System; 272using System.Data; 273using System.Data.OleDb; 274 275class TestADO 276{ 277 static void Main(string[] args) 278 { 279 string strDSN = Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\test.mdb; 280 string strSQL = SELECT * FROM employee ; 281 282 OleDbConnection conn = new OleDbConnection(strDSN); 283 OleDbDataAdapter cmd = new OleDbDataAdapter( strSQL, conn ); 284 285 conn.Open(); 286 DataSet ds = new DataSet(); 287 cmd.Fill( ds, employee ); 288 DataTable dt = ds.Tables[0]; 289 290 Console.WriteLine(Field Name DataType Unique AutoIncrement AllowNull); 291 Console.WriteLine(==================================================================); 292 foreach( DataColumn dc in dt.Columns ) 293 { 294 Console.WriteLine(dc.ColumnName+ , +dc.DataType + ,+dc.Unique + ,+dc.AutoIncrement+ ,+dc.AllowDBNull ); 295 } 296 conn.Close(); 297 } 298} 299 300ASP.NET方面的 301十四、一个ASP.NET程序： 302<%@ Page Language=C# %> 303<script runat=server> 304 305 void Button1_Click(Object sender, EventArgs e) 306 { 307 Label1.Text=TextBox1.Text; 308 } 309 310</script> 311<html> 312<head> 313</head> 314<body> 315 <form runat=server> 316 <p> 317 <br /> 318 Enter your name: <asp:TextBox id=TextBox1 runat=server></asp:TextBox> 319 </p> 320 <p> 321 <b><asp:Label id=Label1 runat=server Width=247px></asp:Label></b> 322 </p> 323 <p> 324 <asp:Button id=Button1 onclick=Button1_Click runat=server Text=Submit></asp:Button> 325 </p> 326 </form> 327</body> 328</html> 329 330WinForm开发： 331十五、一个简单的WinForm程序： 332using System; 333using System.Drawing; 334using System.Collections; 335using System.ComponentModel; 336using System.Windows.Forms; 337using System.Data; 338 339 340public class SimpleForm : System.Windows.Forms.Form 341{ 342 343 private System.ComponentModel.Container components = null; 344 private System.Windows.Forms.Button button1; 345 private System.Windows.Forms.TextBox textBox1; 346 public SimpleForm() 347 { 348 InitializeComponent(); 349 } 350 351 protected override void Dispose( bool disposing ) 352 { 353 if( disposing ) 354 { 355 if (components != null) 356 { 357 components.Dispose(); 358 } 359 } 360 base.Dispose( disposing ); 361 } 362 363 Windows Form Designer generated code 407 408 [STAThread] 409 static void Main() 410 { 411 Application.Run(new SimpleForm()); 412 } 413} 414十六、运行时显示自己定义的图标： 415//load icon and set to form 416System.Drawing.Icon ico = new System.Drawing.Icon(@c:\temp\app.ico); 417this.Icon = ico; 418十七、添加组件到ListBox中： 419private void Form1_Load(object sender, System.EventArgs e) 420{ 421 string str = First item; 422 int i = 23; 423 float flt = 34.98f; 424 listBox1.Items.Add(str); 425 listBox1.Items.Add(i.ToString()); 426 listBox1.Items.Add(flt.ToString()); 427 listBox1.Items.Add(Last Item in the List Box); 428} 429 430网络方面的： 431十八、取得IP地址： 432using System; 433using System.Net; 434 435class GetIP 436{ 437 public static void Main() 438 { 439 IPHostEntry ipEntry = Dns.GetHostByName (localhost); 440 IPAddress [] IpAddr = ipEntry.AddressList; 441 for (int i = 0; i < IpAddr.Length; i++) 442 { 443 Console.WriteLine (IP Address {0}: {1} , i, IpAddr.ToString ()); 444 } 445 } 446} 447十九、取得机器名称： 448using System; 449using System.Net; 450 451class GetIP 452{ 453 public static void Main() 454 { 455 Console.WriteLine (Host name : {0}, Dns.GetHostName()); 456 } 457} 458二十、发送邮件： 459using System; 460using System.Web; 461using System.Web.Mail; 462 463public class TestSendMail 464{ 465 public static void Main() 466 { 467 try 468 { 469 // Construct a new mail message 470 MailMessage message = new MailMessage(); 471 message.From = from@domain.com; 472 message.To = pengyun@cobainsoft.com; 473 message.Cc = ; 474 message.Bcc = ; 475 message.Subject = Subject; 476 message.Body = Content of message; 477 478 //if you want attach file with this mail, add the line below 479 message.Attachments.Add(new MailAttachment(c:\\attach.txt, MailEncoding.Base64)); 480 481 // Send the message 482 SmtpMail.Send(message); 483 System.Console.WriteLine(Message has been sent); 484 } 485 486 catch(Exception ex) 487 { 488 System.Console.WriteLine(ex.Message.ToString()); 489 } 490 491 } 492} 493二十一、根据IP地址得出机器名称： 494using System; 495using System.Net; 496 497class ResolveIP 498{ 499 public static void Main() 500 { 501 IPHostEntry ipEntry = Dns.Resolve(172.29.9.9); 502 Console.WriteLine (Host name : {0}, ipEntry.HostName); 503 } 504} 505 506GDI+方面的： 507二十二、GDI+入门介绍： 508using System; 509using System.Drawing; 510using System.Collections; 511using System.ComponentModel; 512using System.Windows.Forms; 513using System.Data; 514 515public class Form1 : System.Windows.Forms.Form 516{ 517 private System.ComponentModel.Container components = null; 518 519 public Form1() 520 { 521 InitializeComponent(); 522 } 523 524 protected override void Dispose( bool disposing ) 525 { 526 if( disposing ) 527 { 528 if (components != null) 529 { 530 components.Dispose(); 531 } 532 } 533 base.Dispose( disposing ); 534 } 535 536 Windows Form Designer generated code 546 547 [STAThread] 548 static void Main() 549 { 550 Application.Run(new Form1()); 551 } 552 553 private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e) 554 { 555 Graphics g=e.Graphics; 556 g.DrawLine(new Pen(Color.Blue),10,10,210,110); 557 g.DrawRectangle(new Pen(Color.Red),10,10,200,100); 558 g.DrawEllipse(new Pen(Color.Yellow),10,150,200,100); 559 } 560} 561 562XML方面的： 563二十三、读取XML文件： 564using System; 565using System.Xml; 566 567class TestReadXML 568{ 569 public static void Main() 570 { 571 572 XmlTextReader reader = new XmlTextReader(C:\\test.xml); 573 reader.Read(); 574 575 while (reader.Read()) 576 { 577 reader.MoveToElement(); 578 Console.WriteLine(XmlTextReader Properties Test); 579 Console.WriteLine(===================); 580 581 // Read this properties of element and display them on console 582 Console.WriteLine(Name: + reader.Name); 583 Console.WriteLine(Base URI: + reader.BaseURI); 584 Console.WriteLine(Local Name: + reader.LocalName); 585 Console.WriteLine(Attribute Count: + reader.AttributeCount.ToString()); 586 Console.WriteLine(Depth: + reader.Depth.ToString()); 587 Console.WriteLine(Line Number: + reader.LineNumber.ToString()); 588 Console.WriteLine(Node Type: + reader.NodeType.ToString()); 589 Console.WriteLine(Attribute Count: + reader.Value.ToString()); 590 } 591 } 592} 593二十四、写XML文件： 594using System; 595using System.Xml; 596 597public class TestWriteXMLFile 598{ 599 public static int Main(string[] args) 600 { 601 try 602 { 603 // Creates an XML file is not exist 604 XmlTextWriter writer = new XmlTextWriter(C:\\temp\\xmltest.xml, null); 605 // Starts a new document 606 writer.WriteStartDocument(); 607 //Write comments 608 writer.WriteComment(Commentss: XmlWriter Test Program); 609 writer.WriteProcessingInstruction(Instruction,Person Record); 610 // Add elements to the file 611 writer.WriteStartElement(p, person, urn:person); 612 writer.WriteStartElement(LastName,); 613 writer.WriteString(Chand); 614 writer.WriteEndElement(); 615 writer.WriteStartElement(FirstName,); 616 writer.WriteString(Mahesh); 617 writer.WriteEndElement(); 618 writer.WriteElementInt16(age,, 25); 619 // Ends the document 620 writer.WriteEndDocument(); 621 } 622 catch (Exception e) 623 { 624 Console.WriteLine (Exception: {0}, e.ToString()); 625 } 626 return 0; 627 } 628} 629 630Web Service方面的： 631二十五、一个Web Service的小例子： 632<% @WebService Language=C# Class=TestWS %> 633 634using System.Web.Services; 635 636public class TestWS : System.Web.Services.WebService 637{ 638 [WebMethod()] 639 public string StringFromWebService() 640 { 641 return This is a string from web service.; 642 } 643} 644
