如何創建IP地址和端口到NSData中以便與

Question

我正在使用名爲GCDAsyncUDPSocket的庫，並且有一種方法要求我將IP地址和端口作爲NSData傳遞。

感謝您的幫助。

Answer 1

從頭文件：

* Binds the UDP socket to the given address, specified as a sockaddr structure wrapped in a NSData object. 
* 
* If you have an existing struct sockaddr you can convert it to a NSData object like so: 
* struct sockaddr sa -> NSData *dsa = [NSData dataWithBytes:&remoteAddr length:remoteAddr.sa_len]; 
* struct sockaddr *sa -> NSData *dsa = [NSData dataWithBytes:remoteAddr length:remoteAddr->sa_len]; 

所以，你需要一個sockaddr：

#include <netinet/in.h> 
#include <arpa/inet.h> 

struct sockaddr_in ip; 
ip.sin_family = AF_INET; 
ip.sin_port = htons(6003); 
inet_pton(AF_INET, "0.0.0.0", &ip.sin_addr); 

NSData * discoveryHost = [NSData dataWithBytes:&ip length:ip.sin_len]; 

這裏有sockaddr一些文檔 - 在Xcode 5.1.1本http://www.beej.us/guide/bgnet/output/html/multipage/sockaddr_inman.html