C# 串口通信的问题
我想调用API实现modem拨打电话; 
 如何实现? 
 我在网上找到CommPort   代码? 
 不知道如何向其发送AT命令拨号呢?   
             还请各位大侠指教。最好有代码。非常感谢! 
------解决方案--------------------using System; 
 using System.Runtime.InteropServices;   
 namespace JustinIO { 
 	class CommPort {   
 		public int PortNum;  
 		public int BaudRate; 
 		public byte ByteSize; 
 		public byte Parity; // 0-4=no,odd,even,mark,space  
 		public byte StopBits; // 0,1,2 = 1, 1.5, 2  
 		public int ReadTimeout;  		 
 		//comm port win32 file handle 
 		private int hComm = -1;  		 
 		public bool Opened = false;  		  
 		//win32 api constants 
 		  private const uint GENERIC_READ = 0x80000000; 
 		  private const uint GENERIC_WRITE = 0x40000000; 
 		  private const int OPEN_EXISTING = 3;		 
 		  private const int INVALID_HANDLE_VALUE = -1;  		 
 		[StructLayout(LayoutKind.Sequential)] 
 		public struct DCB { 
 			//taken from c struct in platform sdk  
 			public int DCBlength;           // sizeof(DCB)  
 			public int BaudRate;            // current baud rate 
 			/* these are the c struct bit fields, bit twiddle flag to set 
 			public int fBinary;          // binary mode, no EOF check  
 			public int fParity;          // enable parity checking  
 			public int fOutxCtsFlow;      // CTS output flow control  
 			public int fOutxDsrFlow;      // DSR output flow control  
 			public int fDtrControl;       // DTR flow control type  
 			public int fDsrSensitivity;   // DSR sensitivity  
 			public int fTXContinueOnXoff; // XOFF continues Tx  
 			public int fOutX;          // XON/XOFF out flow control  
 			public int fInX;           // XON/XOFF in flow control  
 			public int fErrorChar;     // enable error replacement  
 			public int fNull;          // enable null stripping  
 			public int fRtsControl;     // RTS flow control  
 			public int fAbortOnError;   // abort on error  
 			public int fDummy2;        // reserved  
 			*/ 
 			public uint flags; 
 			public ushort wReserved;          // not currently used  
 			public ushort XonLim;             // transmit XON threshold  
 			public ushort XoffLim;            // transmit XOFF threshold  
 			public byte ByteSize;           // number of bits/byte, 4-8  
 			public byte Parity;             // 0-4=no,odd,even,mark,space  
 			public byte StopBits;           // 0,1,2 = 1, 1.5, 2  
 			public char XonChar;            // Tx and Rx XON character  
 			public char XoffChar;           // Tx and Rx XOFF character  
 			public char ErrorChar;          // error replacement character  
 			public char EofChar;            // end of input character  
 			public char EvtChar;            // received event character  
 			public ushort wReserved1;         // reserved; do not use  
 		}
------解决方案--------------------没有命令结束符