按htons的定义返回的是16位无符号整数。
上面的例子36895应该才是对的，用在BINTOC函数时要判断转换为16位有符号整数。

应该是我理解错了，还是要经过htons()的转换
不过咱们应用环境比较固定，vfp9,所以bintoc(nPort-2^15,"2r")也算正确吧

[此贴子已经被作者于2025-10-8 10:16编辑过]

不用htons()也可以，就是大小端转换，即16位的低8位与高8位互换。
用VFP的位运算函数就可以。

bintoc函数中的参数“R”可以实现自动翻转功能

SET CENTURY on
SET DATE ANSI
SET HOURS TO 24
CLEAR

fh=_GetNetTime("128.138.140.44",13)
?zh(fh)
retu
retu

FUNCTION _GetNetTime(szNtpIP, ddNtpPort)
LOCAL stWsaData, stSockAddr, szBuffer, dhSocket
LOCAL i, ddLen,ret

DECLARE LONG WSAStartup  IN "Ws2_32" LONG, STRING@
DECLARE LONG WSACleanup  IN "Ws2_32"
DECLARE LONG socket      IN "Ws2_32" LONG, LONG, LONG
DECLARE LONG connect     IN "Ws2_32" LONG, STRING@, LONG
DECLARE LONG recv        IN "Ws2_32" LONG, STRING@, LONG, LONG
DECLARE LONG closesocket IN "Ws2_32" LONG
DECLARE LONG inet_addr   IN "Ws2_32" STRING@
DECLARE LONG htons       IN "Ws2_32" LONG
DECLARE INTEGER gethostbyname in WSOCK32 String@
DECLARE LONG inet_ntoa     IN "Ws2_32" LONG

stWsaData  = REPLICATE(0h00, 398)
szBuffer   = REPLICATE(0h00, 256)
stSockAddr = REPLICATE(0h00, 16)

WSAStartup(0x202, @stWsaData)
dhSocket = socket(2, 1, 6)
IF ISDIGIT(szNtpIP)
    stSockAddr = 0h0200;
        + BINTOC(htons(ddNtpPort), "2RS");
        + BINTOC(inet_addr(@szNtpIP), "4RS");
        + REPLICATE(0h00, 8)
else
    RET = CTOBIN(SYS(2600, gethostbyname(@szNtpIP) + 12, 4), "4RS")  &&偏移12，IP地址列表
    RET = CTOBIN(SYS(2600, RET, 4), "4RS")  &&IP地址
    stSockAddr = 0h0200;
        + BINTOC(htons(ddNtpPort), "2RS");
        + SYS(2600, RET, 4);
        + REPLICATE(0h00, 8)
endif
ddLen  = 0
IF connect(dhSocket, @stSockAddr, LEN(stSockAddr)) = -1
    ?"连接失败"
else
    FOR i = 1 TO 3
        ddLen = recv(dhSocket, @szBuffer, LEN(szBuffer), 0)
        IF ddLen != -1
            EXIT
        ENDIF
    ENDFOR
endif
closesocket(dhSocket)
WSACleanup()
IF ddLen > 0
    szBuffer = LEFT(szBuffer, ddLen)
    RETURN szBuffer
ELSE
*        MESSAGEBOX("网络异常，时间同步失败")
    RETURN ""
ENDIF
ENDFUNC

PROCEDURE zh
LPARAMETERS szutc
IF EMPTY(szutc)
else
    ddYear   = INT(VAL(SUBSTR(szUTC, 8, 2))) + 2000
    ddMonth  = INT(VAL(SUBSTR(szUTC, 11, 2)))
    ddDay    = INT(VAL(SUBSTR(szUTC, 14, 2)))
    ddHour   = INT(VAL(SUBSTR(szUTC, 17, 2)))
    ddMinute = INT(VAL(SUBSTR(szUTC, 20, 2)))
    ddSecond = INT(VAL(SUBSTR(szUTC, 23, 2)))
    RETURN DATETIME(ddYear,ddMonth,ddDay,ddHour,ddMinute,ddSecond)+8*3600
endif
RETURN ""
获取网络时间，代码都是从网上抄的，又随意改的，测试htons，发现用bintoc(nPort-2^15,"2")才是正确的
因为这里经过htons转换后又加了个参数r，搞不懂了
stSockAddr = 0h0200;
        + BINTOC(htons(ddNtpPort), "2RS");
        + BINTOC(inet_addr(@szNtpIP), "4RS");
        + REPLICATE(0h00, 8)
只能这样改
stSockAddr = 0h0200;
        + BINTOC(ddNtpPort-2^15, "2");
        + BINTOC(inet_addr(@szNtpIP), "4RS");
        + REPLICATE(0h00, 8)

[此贴子已经被作者于2025-10-8 10:55编辑过]

通过ntp获取时间，网上说端口是123，可我测试发现只有端口13才可以获取，123却连接失败
这几个都可以获取网络时间，但端口都是13才可以
"time-a.nist.gov"
"time-b.nist.gov"
"128.138.140.44"

这个是udp协议，最后接收失败，没有调试成功，通过NTP获取网络时间
    DECLARE INTEGER WSAGetLastError IN ws2_32
   
    * 初始化Winsock
    DECLARE INTEGER WSAStartup IN ws2_32 INTEGER, STRING @
    DECLARE INTEGER WSACleanup IN ws2_32
   
    lcWSAData = REPLI(CHR(0), 400)
    IF WSAStartup(0x202, @lcWSAData) != 0
        ? "Winsock初始化失败"
        RETURN
    ENDIF
   
    * 创建UDP Socket
    DECLARE INTEGER socket IN ws2_32 INTEGER, INTEGER, INTEGER
    DECLARE INTEGER closesocket IN ws2_32 INTEGER
   
    lnSocket = socket(2, 2, 17)  && AF_INET, SOCK_DGRAM, IPPROTO_UDP
    IF lnSocket = -1
        ? "Socket创建失败: " + TRANSFORM(WSAGetLastError())
        WSACleanup()
        RETURN
    ENDIF
   
    * 设置超时
    DECLARE INTEGER setsockopt IN ws2_32 INTEGER, INTEGER, INTEGER, STRING @, INTEGER
    lcTimeout = num2dword(5000)  && 5秒超时
    setsockopt(lnSocket, 0xFFFF, 0x1006, @lcTimeout, 4)  && SO_RCVTIMEO
   
    * 构建NTP请求
    lcNTPData = CHR(0x1B) + REPLI(CHR(0), 47)
   
    * 发送到NTP服务器
    DECLARE INTEGER sendto IN ws2_32 INTEGER, STRING @, INTEGER, INTEGER, STRING @, INTEGER
    DECLARE INTEGER inet_addr IN ws2_32 STRING
    DECLARE short htons       IN "Ws2_32" short
   
    lnServerIP = inet_addr("120.25.115.20")  && 阿里云NTP服务器IP
   
    lcSockAddr = 0h0200+ num2word(123)+num2dword(lnServerIP) + REPLI(CHR(0), 8)
    IF sendto(lnSocket, @lcNTPData, 48, 0, @lcSockAddr, 16) = -1
        ? "发送失败: " + TRANSFORM(WSAGetLastError())
        closesocket(lnSocket)
        WSACleanup()
        RETURN
    ENDIF
   
    ? "请求发送成功，等待响应..."
   
    * 接收响应
    DECLARE INTEGER recvfrom IN ws2_32 INTEGER, STRING @, INTEGER, INTEGER, STRING @, INTEGER @
   
    lcBuffer = REPLI(CHR(0), 1024)
    lcFromAddr = REPLI(CHR(0), 16)
    lnAddrLen = 16
   
    lnReceived = recvfrom(lnSocket, @lcBuffer, 1024, 0, @lcFromAddr, @lnAddrLen)
    IF lnReceived >= 48
        ? "收到响应，长度: " + TRANSFORM(lnReceived)
        * 解析时间...
    ELSE
        ? "接收失败: " + TRANSFORM(WSAGetLastError())
    ENDIF
   
    closesocket(lnSocket)
    WSACleanup()

FUNCTION num2dword(lnValue)
    LOCAL lcResult, i
    lcResult = ""
    FOR i = 3 TO 0 STEP -1
        lcResult = lcResult + CHR(BITRSHIFT(lnValue, i*8) % 256)
    ENDFOR
    RETURN lcResult
ENDFUNC

FUNCTION num2word(lnValue)
    RETURN CHR(BITRSHIFT(lnValue, 8) % 256) + CHR(lnValue % 256)
ENDFUNC

你这段代码htons函数声明不对，和我一样申明为long或integer了！

都是网上抄的代码，不知其所以然，不过可以运行一下代码试试，先调试通过再修改BUG

DECLARE INTEGER WSAGetLastError IN ws2_32

* 初始化Winsock
DECLARE INTEGER WSAStartup IN ws2_32 INTEGER, STRING @
DECLARE INTEGER WSACleanup IN ws2_32

lcWSAData = REPLI(CHR(0), 400)
IF WSAStartup(0x202, @lcWSAData) != 0
    ? "Winsock初始化失败"
    RETURN
ENDIF

* 创建UDP Socket
DECLARE INTEGER socket IN ws2_32 INTEGER, INTEGER, INTEGER
DECLARE INTEGER closesocket IN ws2_32 INTEGER

lnSocket = socket(2, 2, 17)  && AF_INET, SOCK_DGRAM, IPPROTO_UDP
IF lnSocket = -1
    ? "Socket创建失败: " + TRANSFORM(WSAGetLastError())
    WSACleanup()
    RETURN
ENDIF
* 设置超时
DECLARE INTEGER setsockopt IN ws2_32 INTEGER, INTEGER, INTEGER, STRING @, INTEGER
lcTimeout = BINTOC(5000,"4s")  && 5秒超时
setsockopt(lnSocket, 0xFFFF, 0x1006, @lcTimeout, 4)  && SO_RCVTIMEO
* 构建NTP请求
lcNTPData = CHR(0x1B) + REPLI(CHR(0), 47)

* 发送到NTP服务器
DECLARE INTEGER sendto IN ws2_32 INTEGER, STRING @, INTEGER, INTEGER, STRING @, INTEGER
DECLARE INTEGER inet_addr IN ws2_32 STRING

lnServerIP = inet_addr("120.25.115.20")  && 阿里云NTP服务器IP
*lnServerIP = inet_addr("202.120.2.101")  &&国家授时中心

lcSockAddr = 0h0200+ bintoc(123,"2s")+bintoc(lnServerIP-2^31,"4r") + REPLI(CHR(0), 8)
IF sendto(lnSocket, @lcNTPData, 48, 0, @lcSockAddr, 16) = -1
    ? "发送失败: " + TRANSFORM(WSAGetLastError())
    closesocket(lnSocket)
    WSACleanup()
    RETURN
ENDIF

? "请求发送成功，等待响应..."

* 接收响应
DECLARE INTEGER recvfrom IN ws2_32 INTEGER, STRING @, INTEGER, INTEGER, STRING @, INTEGER @

lcBuffer = REPLI(CHR(0), 1024)
lcFromAddr = REPLI(CHR(0), 16)
lnAddrLen = 16
lnReceived = recvfrom(lnSocket, @lcBuffer, 1024, 0, @lcFromAddr, @lnAddrLen)
IF lnReceived >= 48
    ? "收到响应，长度: " + TRANSFORM(lnReceived)
    lnTransmitSec = ctobin(SUBSTR(lcBuffer, 41, 4))+2^31
    lnTransmitFrac = (ctobin(SUBSTR(lcBuffer, 45, 4))+2^31)/4294967296
    ?DATETIME(1970,1,1,0,0,0)+lnTransmitSec-2208988800+8*60*60
ELSE
    ? "接收失败: " + TRANSFORM(WSAGetLastError())
ENDIF
closesocket(lnSocket)
WSACleanup()
retu
调试通过

[此贴子已经被作者于2025-10-8 22:11编辑过]