POS机精确走纸

private IntPtr iHandle;
                private FileStream fs;
                private StreamWriter sw;

                private string prnPort = "LPT1";   //打印机端口

                public ClsPrintLPT( )
                {

                }

                private const uint GENERIC_READ = 0x80000000;
                private const uint GENERIC_WRITE = 0x40000000;
                private const int OPEN_EXISTING = 3;

                /// <summary>
                /// 打开一个vxd(设备)
                /// </summary>
                [DllImport( "kernel32.dll", EntryPoint = "CreateFile", CharSet = CharSet.Auto )]
                private static extern IntPtr CreateFile( string lpFileName, uint dwDesiredAccess, int dwShareMode, int lpSecurityAttributes,
                                                        int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile );

                /// <summary>
                /// 开始连接打印机
                /// </summary>
                private bool PrintOpen( )
                {
                        iHandle = CreateFile( prnPort, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0 );

                        if ( iHandle.ToInt32( ) == -1 )
                        {
                                MessageBox.Show( "没有连接打印机或者打印机端口不是LPT1！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information );
                                return false;
                        }
                        else
                        {
                                fs = new FileStream( iHandle, FileAccess.ReadWrite );
                                sw = new StreamWriter( fs, System.Text.Encoding.Default );   //写数据
                                return true;
                        }
                }

                /// <summary>
                /// 打印字符串
                /// </summary>
                /// <param name="str">要打印的字符串</param>
                private void PrintLine( string str )
                {
                        sw.WriteLine( str );
                        ;
                }

                /// <summary>
                /// 关闭打印连接
                /// </summary>
                private void PrintEnd( )
                {
                        sw.Close( );
                        fs.Close( );
                }

                /// <summary>
                /// 打印票据
                /// </summary>
                /// <param name="ds">tb_Temp 全部字段数据集合</param>
                /// <returns>true：打印成功 false：打印失败</returns>
                public bool PrintDataSet( string[ ] dsPrint )
                {
                        try
                        {
                                if ( PrintOpen( ) )
                                {
                                        PrintLine( " " );
                                        PrintLine( "[家乐福郑州旗舰店超市]" );
                                        PrintLine( "Name   :      " + dsPrint[ 0 ] );
                                        PrintLine( "Age    :      " + dsPrint[ 1 ] );
                                        PrintLine( "Gender :      " + dsPrint[ 2 ] );
                                        PrintLine( "Beauty :      " + dsPrint[ 3 ] );
                                        PrintLine( "Married:      " + dsPrint[ 4 ] );
                                        PrintLine( "-------------------------------------------" );
                                }
                                PrintEnd( );

                                return true;
                        }
                        catch
                        {
                                return false;
                        }
                }

                /// <summary>
                /// ESC/P 指令
                /// </summary>
                /// <param name="iSelect">0：退纸命令 1：进纸命令 2：换行命令</param>
                public void PrintESC( int iSelect )
                {
                        string send;

                        iHandle = CreateFile( prnPort, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0 );

                        if ( iHandle.ToInt32( ) == -1 )
                        {
                                MessageBox.Show( "没有连接打印机或者打印机端口不是LPT1！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information );
                        }
                        else
                        {
                                fs = new FileStream( iHandle, FileAccess.ReadWrite );
                        }

                        byte[ ] buf = new byte[ 80 ];

                        switch ( iSelect )
                        {
                                case 0:
                                        //send = "" + ( char )( 27 ) + ( char )( 64 ) + ( char )( 27 ) + 'j' + ( char )( 255 );    //退纸1 255 为半张纸长
                                        //send = send + ( char )( 27 ) + 'j' + ( char )( 125 );    //退纸2
                                        send = "" + ( char )( 27 ) + ( char )( 64 ) + ( char )( 27 ) + 'j' + ( char )( 110 );    //退纸1 255 为半张纸长
                                        send = send + ( char )( 27 ) + 'j' + ( char )( 125 );    //退纸2
                                        break;
                                case 1:
                                        send = "" + ( char )( 27 ) + ( char )( 64 ) + ( char )( 27 ) + 'J' + ( char )( 255 );    //进纸
                                        break;
                                case 2:
                                        send = "" + ( char )( 27 ) + ( char )( 64 ) + ( char )( 12 );   //换行
                                        break;
                                default:
                                        send = "" + ( char )( 27 ) + ( char )( 64 ) + ( char )( 12 );   //换行
                                        break;
                        }

                        for ( int i = 0; i < send.Length; i++ )
                        {
                                buf[ i ] = ( byte )send[ i ];
                        }

                        fs.Write( buf, 0, buf.Length );
                        fs.Close( );
                }
        }
 
然后再打印时，调用进纸或者退职命令即可！
PrintDocument.Print();
Instance.PrintESC(0);