Qt 如何根据ping值结果返回网络状态

[晋晔]

例如根据这个结果：

我便可知道网络状态是通的。
根据这个结果

我便知道网络状态是断开的

[foruok]

QProcess调用命令行，读取标准输出即可。

[晋晔]

引用 1 楼 foruok 的回复:

QProcess调用命令行，读取标准输出即可。

for叔，有没有一个函数，可以返回 0或者1结果，通过返回结果可直接获得网络是通还是不通。

[foruok]

引用 2 楼 xuebijishui 的回复:

[quote=引用 1 楼 foruok 的回复:] QProcess调用命令行，读取标准输出即可。

for叔，有没有一个函数，可以返回 0或者1结果，通过返回结果可直接获得网络是通还是不通。[/quote] 宝宝，你要求有点高了……

[donwmufromdying]

个人不建议使用QProcess调用命令行然后解析返回字符串来判断。我曾经用过这种方法，会程序崩溃。我的代码是完全没问题。后来我是重写了ping来实现的。就是自己从更底层去实现这个ping,其实代码量不大的。源码也是有标准的。你拿下来改改就OK

[donwmufromdying]

typedef struct tagIPHDR
    {
        u_char VIHL; // Version and IHL
        u_char TOS; // Type Of Service
        short TotLen; // Total Length
        short ID; // Identification
        short FlagOff; // Flags and Fragment Offset
        u_char TTL; // Time To Live
        u_char Protocol; // Protocol
        u_short Checksum; // Checksum
        struct in_addr iaSrc; // Internet Address - Source
        struct in_addr iaDst; // Internet Address - Destination
    }IPHDR, *PIPHDR;

    // ICMP Header - RFC 792
    typedef struct tagICMPHDR
    {
        u_char Type; // Type
        u_char Code; // Code
        u_short Checksum; // Checksum
        u_short ID; // Identification
        u_short Seq; // Sequence
        char Data; // Data
    }ICMPHDR, *PICMPHDR;

    // ICMP Echo Request
    typedef struct tagECHOREQUEST
    {
        ICMPHDR icmpHdr;
        struct timeval echoTime;
        char cData[32];
    }ECHOREQUEST, *PECHOREQUEST;

    // ICMP Echo Reply
    typedef struct tagECHOREPLY
    {
        IPHDR ipHdr;
        ECHOREQUEST echoRequest;
        char cFiller[256];
    }ECHOREPLY, *PECHOREPLY;

bool Utilities::ping(const char *hostName)
{
    if (NULL == hostName)
    {
        XgsLogger::log("", QtWarningMsg, "(%s,%d), Invalid IP address!", __FILE__, __LINE__ );
        return false;
    }
    int sockfd = 0;
    int nRet;
    int nCount;
    int iSuccess = 0;
    struct sockaddr_in addrDest;
    struct hostent *Dest;
    float spenttime;

    if ((Dest=gethostbyname(hostName)) == NULL)
    {
        return false;
    }
    if((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
    {
        return false;
    }

    memset((char *)&addrDest, 0, sizeof(struct sockaddr_in));
    addrDest.sin_addr = *((struct in_addr *)Dest->h_addr);
    addrDest.sin_family = AF_INET;
    bzero(&(addrDest.sin_zero), sizeof( addrDest.sin_zero ) );

    ECHOREQUEST echoReq;
    memset((ECHOREQUEST*)&echoReq, 0, sizeof(struct tagECHOREQUEST));
    echoReq.icmpHdr.Type = ICMP_ECHO;
    echoReq.icmpHdr.Code = 0;
    echoReq.icmpHdr.ID = getpid();
    int Seq = 0;
    for (nRet = 0; nRet < 32; nRet++)
        echoReq.cData[nRet] = ' '+nRet;
    nCount = 0;
    while(nCount < 3)
    {
        echoReq.icmpHdr.Seq = Seq++;
        echoReq.icmpHdr.Checksum = 0;
        gettimeofday(&echoReq.echoTime,NULL);
        echoReq.icmpHdr.Checksum = checksum((unsigned short*)&echoReq, sizeof(struct tagECHOREQUEST));
        if (sendto(sockfd, (ECHOREQUEST*)&echoReq, sizeof(tagECHOREQUEST), 0, (struct sockaddr *)&addrDest, sizeof(addrDest)) < 0)
        {
            close(sockfd);
            return false;
        }
        if(WaitForEchoReply(sockfd) == -1)
        {
            close(sockfd);
            return false;
        }
        ECHOREPLY icmpRecv;
        int addr_len;
        addr_len = sizeof(struct sockaddr);
        if (recvfrom(sockfd, (ECHOREPLY*)&icmpRecv, sizeof(struct tagECHOREPLY), 0, (struct sockaddr *)&addrDest, (socklen_t *)&addr_len) < 0)
        {

            close(sockfd);
            return false;
        }
        else if(icmpRecv.echoRequest.icmpHdr.Type == ICMP_ECHOREPLY)
        {
            gettimeofday(&icmpRecv.echoRequest.echoTime, NULL);
            tv_sub(&icmpRecv.echoRequest.echoTime, &echoReq.echoTime);
            spenttime=icmpRecv.echoRequest.echoTime.tv_sec*1000+icmpRecv.echoRequest.echoTime.tv_usec*0.001;
            if (strcmp(Dest->h_name, inet_ntoa(icmpRecv.ipHdr.iaSrc))==0)
            {
                iSuccess ++;
            //	printf("Reply from %s: Bytes=%d Id_seq = %d time=%4.3fms TTL=%d\n",/*Dest->h_name*/inet_ntoa(icmpRecv.ipHdr.iaSrc), sizeof(icmpRecv.echoRequest), icmpRecv.echoRequest.icmpHdr.Seq, spenttime,icmpRecv.ipHdr.TTL);
            }
            else
            {
            ;	//printf("From %s Id_seq %d Destination Host Unreachable ", inet_ntoa(icmpRecv.ipHdr.iaSrc), icmpRecv.echoRequest.icmpHdr.Seq);
            }
        //	sleep(1);
        }
        nCount ++;
    }

    close(sockfd);
    if (iSuccess >0)
        return true;
    else
        return false;

}

[feiyangqingyun]

我的方法更暴力更另类！用起来爽歪歪，毫无压力！

//判断IP地址及端口是否在线
    static bool IPLive(QString ip, int port, int timeout = 1000) {
        QTcpSocket tcpClient;
        tcpClient.abort();
        tcpClient.connectToHost(ip, port);
        //100毫秒没有连接上则判断不在线
        return tcpClient.waitForConnected(timeout);
    }
//判断是否通外网
    static bool IsWebOk() {
        //能接通百度IP说明可以通外网
        return IPLive("115.239.211.112", 80);
    }

[wain_]

学习了

[在飞的特拉斯]

引用 6 楼 feiyangqingyun 的回复:

我的方法更暴力更另类！用起来爽歪歪，毫无压力！

//判断IP地址及端口是否在线
    static bool IPLive(QString ip, int port, int timeout = 1000) {
        QTcpSocket tcpClient;
        tcpClient.abort();
        tcpClient.connectToHost(ip, port);
        //100毫秒没有连接上则判断不在线
        return tcpClient.waitForConnected(timeout);
    }
//判断是否通外网
    static bool IsWebOk() {
        //能接通百度IP说明可以通外网
        return IPLive("115.239.211.112", 80);
    }

确实很暴力，但是100ms标准哪里来的呢？