VC UDP接收发送广播

港控/mmm° 2022-12-19 03:53 142阅读 0赞

### 测试环境： ###

Visual Studio 2013

Windows 10

VC MFC

UDP远程：ARM Linux C语言程序

### 效果： ###

win程序，button1单击向192.168.168.255发送字符串："\{"Cmd":"GetDeviceInfo"\}" ARM板收到返回设备信息

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70][]

ARM板上程序打印信息：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NuaWNmaG51aQ_size_16_color_FFFFFF_t_70 1][]

### VC代码： ###

全局变量

int UDP_Sock_FD = -1;// 套接字
    struct sockaddr_in remote_addr;// 远程，即要发送到的地方
    struct sockaddr_in local_addr;// 本地，本地的IP端口

初始化部分，放在程序初始化中

// 创建套接字 
    	UDP_Sock_FD = socket(AF_INET, SOCK_DGRAM, 0);
    	if (UDP_Sock_FD < 0){
    		printf("创建套接字失败\n");
    	}else{
    		printf("创建套接字成功%d\n", UDP_Sock_FD);
    	}
    	int optval = 1;//这个值一定要设置，否则可能导致sendto()失败
    	setsockopt(UDP_Sock_FD, SOL_SOCKET, SO_REUSEADDR, (const char *)&optval, sizeof(int));
    
    	// 本地端口和地址
    	memset(&local_addr, 0, sizeof(struct sockaddr_in));
    	memset(&local_addr, 0, sizeof(local_addr));
    	local_addr.sin_family = AF_INET;
    	local_addr.sin_port = htons(1257);
    	local_addr.sin_addr.s_addr = INADDR_ANY;
    
    	// 目标端口和地址
    	memset(&remote_addr, 0, sizeof(struct sockaddr_in));
    	remote_addr.sin_family = AF_INET;
    	remote_addr.sin_port = htons(1258);
    	remote_addr.sin_addr.s_addr = inet_addr("192.168.168.255");//htonl(INADDR_BROADCAST);
    	memset(remote_addr.sin_zero, 0, sizeof(remote_addr.sin_zero));
    	printf("创建套接字成功%d\n", remote_addr.sin_addr.s_addr);
    
    	// 绑定
    	int ret = bind(UDP_Sock_FD, (struct sockaddr *)&local_addr, sizeof(struct sockaddr));
    	if (ret < 0){
    		printf("绑定失败\n");
    	}else{
    		printf("绑定成功 %d\n", ret);
    	}

发送函数，放在按钮事件函数或其它触发函数

int sendBytes = 0;
    	char msg[128] = "{\"Cmd\":\"GetDeviceInfo\"}";
    	if (sendBytes = sendto(UDP_Sock_FD, (char*)msg, strlen(msg), 0, (sockaddr*)&remote_addr, sizeof(remote_addr)) == SOCKET_ERROR){
    		printf("sendto fail, errno=%d\n", errno);
    		return;
    	}
    	printf("msg=%s, msgLen=%d, sendBytes=%d\n", msg, strlen(msg), sendBytes);

UDP接收部分，放在线程中

// 接收字节数，缓存定义
        int recvbytes;
    	char recvbuf[1024];
        // 接收部分，放在while中
    	memset(recvbuf, 0, sizeof(recvbuf));
    	int addrLen = sizeof(struct sockaddr_in);
    	if ((recvbytes = recvfrom(UDP_Sock_FD, recvbuf, 1024, 0,(struct sockaddr *)&local_addr, &addrLen)) != -1){
    		recvbuf[recvbytes] = '\0';
    		printf("Receive UDP Msg Port:%d IP:%s Messgse:%s\n", ntohs(local_addr.sin_port), inet_ntoa(local_addr.sin_addr), recvbuf);
    	}else{
    		printf("recvfrom fail\n");
    	}

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