C#入门代码,csharp

C#入门代码,csharp一、从控制台读取东西代码片断：usingSystem;classTestReadConsole{publicstaticvoidMain(){Console.Write(Enteryourname:);stringstrName=Console.ReadLine();Console.WriteLine(Hi+strName);}}二、读文件代码片断：usingSystem;usingSystem.IO;publicclassTestReadFile{publicstaticvoidMain(String[]args){//ReadtextfileC:\temp\test.txtFileStreamfs=newFileStream(@c:\temp\test.txt,FileMode.Open,FileAccess.Read);StreamReadersr=newStreamReader(fs);Stringline=sr.ReadLine();while(line!=null){Console.WriteLine(line);line=sr.ReadLine();}sr.Close();fs.Close();}}三、写文件代码：usingSystem;usingSystem.IO;publicclassTestWriteFile{publicstaticvoidMain(String[]args){//CreateatextfileC:\temp\test.txtFileStreamfs=newFileStream(@c:\temp\test.txt,FileMode.OpenOrCreate,FileAccess.Write);StreamWritersw=newStreamWriter(fs);//WritetothefileusingStreamWriterclasssw.BaseStream.Seek(0,SeekOrigin.End);sw.WriteLine(FirstLine);sw.WriteLine(SecondLine);sw.Flush();}}四、拷贝文件：usingSystem;usingSystem.IO;classTestCopyFile{publicstaticvoidMain(){File.Copy(c:\\temp\\source.txt,C:\\temp\\dest.txt);}}五、移动文件：usingSystem;usingSystem.IO;classTestMoveFile{publicstaticvoidMain(){File.Move(c:\\temp\\abc.txt,C:\\temp\\def.txt);}}六、使用计时器：usingSystem;usingSystem.Timers;classTestTimer{publicstaticvoidMain(){Timertimer=newTimer();timer.Elapsed+=newElapsedEventHandler(DisplayTimeEvent);timer.Interval=1000;timer.Start();timer.Enabled=true;while(Console.Read()!='q'){//-------------}}publicstaticvoidDisplayTimeEvent(objectsource,ElapsedEventArgse){Console.Write(\r{0},DateTime.Now);}}七、调用外部程序：classTest{staticvoidMain(string[]args){System.Diagnostics.Process.Start(notepad.exe);}}方面的：八、连接Access数据库：usingSystem;usingSystem.Data;usingSystem.Data.OleDb;classTestADO{staticvoidMain(string[]args){stringstrDSN=Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\\test.mdb;stringstrSQL=SELECT*FROMemployees;OleDbConnectionconn=newOleDbConnection(strDSN);OleDbCommandcmd=newOleDbCommand(strSQL,conn);OleDbDataReaderreader=null;try{conn.Open();reader=cmd.ExecuteReader();while(reader.Read()){Console.WriteLine(FirstName:{0},LastName:{1},reader[FirstName],reader[LastName]);}}catch(Exceptione){Console.WriteLine(e.Message);}finally{conn.Close();}}}九、连接SQLServer数据库：usingSystem;usingSystem.Data.SqlClient;publicclassTestADO{publicstaticvoidMain(){SqlConnectionconn=newSqlConnection(DataSource=localhost;IntegratedSecurity=SSPI;InitialCatalog=pubs);SqlCommandcmd=newSqlCommand(SELECT*FROMemployees,conn);try{conn.Open();SqlDataReaderreader=cmd.ExecuteReader();while(reader.Read()){Console.WriteLine(FirstName:{0},LastName:{1},reader.GetString(0),reader.GetString(1));}reader.Close();conn.Close();}catch(Exceptione){Console.WriteLine(ExceptionOccured--{0},e);}}}十、从SQL内读数据到XML：usingSystem;usingSystem.Data;usingSystem.Xml;usingSystem.Data.SqlClient;usingSystem.IO;publicclassTestWriteXML{publicstaticvoidMain(){StringstrFileName=c:/temp/output.xml;SqlConnectionconn=newSqlConnection(server=localhost;uid=sa;pwd=;database=db);StringstrSql=SELECTFirstName,LastNameFROMemployees;SqlDataAdapteradapter=newSqlDataAdapter();adapter.SelectCommand=newSqlCommand(strSql,conn);//BuildtheDataSetDataSetds=newDataSet();adapter.Fill(ds,employees);//GetaFileStreamobjectFileStreamfs=newFileStream(strFileName,FileMode.OpenOrCreate,FileAccess.Write);//ApplytheWriteXmlmethodtowriteanXMLdocumentds.WriteXml(fs);fs.Close();}}十一、用ADO添加数据到数据库中：usingSystem;usingSystem.Data;usingSystem.Data.OleDb;classTestADO{staticvoidMain(string[]args){stringstrDSN=Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\test.mdb;stringstrSQL=INSERTINTOEmployee(FirstName,LastName)VALUES('FirstName','LastName');//createObjectsofADOConnectionandADOCommandOleDbConnectionconn=newOleDbConnection(strDSN);OleDbCommandcmd=newOleDbCommand(strSQL,conn);try{conn.Open();cmd.ExecuteNonQuery();}catch(Exceptione){Console.WriteLine(Oooops.Ididitagain:\n{0},e.Message);}finally{conn.Close();}}}十二、使用OLEConn连接数据库：usingSystem;usingSystem.Data;usingSystem.Data.OleDb;classTestADO{staticvoidMain(string[]args){stringstrDSN=Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\test.mdb;stringstrSQL=SELECT*FROMemployee;OleDbConnectionconn=newOleDbConnection(strDSN);OleDbDataAdaptercmd=newOleDbDataAdapter(strSQL,conn);conn.Open();DataSetds=newDataSet();cmd.Fill(ds,employee);DataTabledt=ds.Tables[0];foreach(DataRowdrindt.Rows){Console.WriteLine(Firstname:+dr[FirstName].ToString()+Lastname:+dr[LastName].ToString());}conn.Close();}}十三、读取表的属性：usingSystem;usingSystem.Data;usingSystem.Data.OleDb;classTestADO{staticvoidMain(string[]args){stringstrDSN=Provider=Microsoft.Jet.OLEDB.4.0;DataSource=c:\test.mdb;stringstrSQL=SELECT*FROMemployee;OleDbConnectionconn=newOleDbConnection(strDSN);OleDbDataAdaptercmd=newOleDbDataAdapter(strSQL,conn);conn.Open();DataSetds=newDataSet();cmd.Fill(ds,employee);DataTabledt=ds.Tables[0];Console.WriteLine(FieldNameDataTypeUniqueAutoIncrementAllowNull);Console.WriteLine(==================================================================);foreach(DataCol