using?System;
using?System.Runtime.InteropServices;
using?System.Text;

namespace?baseStationPDA
{
?class?GPS
?{

??public?string?PortNum;
??public?int?BaudRate;
??public?byte?ByteSize;
??public?byte?Parity;?//?0-4=nooddevenmarkspace
??public?byte?StopBits;?//?012?=?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;????????????//?指定當前波特率?current?baud?rate
???//?these?are?the?c?struct?bit?fields?bit?twiddle?flag?to?set
???public?int?fBinary;??????????//?指定是否允許二進制模式在windows95中必須主TRUE?binary?mode?no?EOF?check
???public?int?fParity;??????????//?指定是否允許奇偶校驗?enable?parity?checking
???public?int?fOutxCtsFlow;??????//?指定CTS是否用于檢測發送控制，當為TRUE是CTS為OFF，發送將被掛起。?CTS?output?flow?control
???public?int?fOutxDsrFlow;??????//?指定CTS是否用于檢測發送控制?DSR?output?flow?control
???public?int?fDtrControl;???????//?DTR_CONTROL_DISABLE值將DTR置為OFF?DTR_CONTROL_ENABLE值將DTR置為ON?DTR_CONTROL_HANDSHAKE允許DTR“握手“?DTR?flow?control?type
???public?int?fDsrSensitivity;???//?當該值為TRUE時DSR為OFF時接收的字節被忽略?DSR?sensitivity
???public?int?fTXContinueOnXoff;?//?指定當接收緩沖區已滿并且驅動程序已經發送出XoffChar字符時發送是否停止。TRUE時，在接收緩沖區接收到緩沖區已滿的字節XoffLim且驅動程序已經發送出XoffChar字符中止接收字節之后，發送繼續進行。　FALSE時，在接收緩沖區接收到代表緩沖區已空的字節XonChar且驅動程序已經發送出恢復發送的XonChar之后，發送繼續進行。XOFF?continues?Tx
???public?int?fOutX;??????????//?TRUE時，接收到XoffChar之后便停止發送接收到XonChar之后將重新開始?XON/XOFF?out?flow?control
???public?int?fInX;???????????//?TRUE時，接收緩沖區接收到代表緩沖區滿的XoffLim之后，XoffChar發送出去接收緩沖區接收到代表緩沖區空的XonLim之后，?XonChar發送出去?XON/XOFF?in?flow?control
???public?int?fErrorChar;?????//?該值為TRUE且fParity為TRUE時，用ErrorChar?成員指定的字符代替奇偶校驗錯誤的接收字符?enable?error?replacement
???public?int?fNull;??????????//?eTRUE時，接收時去掉空（0值）字節?enable?null?stripping
???public?int?fRtsControl;?????//?RTS?flow?control
???/*RTS_CONTROL_DISABLE時RTS置為OFF
???　????????RTS_CONTROL_ENABLE時?RTS置為ON
　　??????????RTS_CONTROL_HANDSHAKE時
　　??????????當接收緩沖區小于半滿時RTS為ON
　???　????????當接收緩沖區超過四分之三滿時RTS為OFF
　　??????????RTS_CONTROL_TOGGLE時
　　??????????當接收緩沖區仍有剩余字節時RTS為ON?否則缺省為OFF*/

???public?int?fAbortonerror;???//?TRUE時有錯誤發生時中止讀和寫操作?abort?on?error
???public?int?fDummy2;????????//?未使用?reserved
???
???public?uint?flags;
???public?ushort?wReserved;??????????//?未使用必須為0?not?currently?used
???public?ushort?XonLim;?????????????//?指定在XON字符發送這前接收緩沖區中可允許的最小字節數?transmit?XON?threshold
???public?ushort?XoffLim;????????????//?指定在XOFF字符發送這前接收緩沖區中可允許的最小字節數?transmit?XOFF?threshold
???public?byte?ByteSize;???????????//?指定端口當前使用的數據位?number?of?bits/byte?4-8
???public?byte?Parity;?????????????//?指定端口當前使