27. 将字典对象转换为 JSON 字符串
+ (NSString *)jsonPrettyStringEncoded:(NSDictionary *)dictionary{
if ([NSJSONSerialization isValidJSONObject:dictionary ]) {
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:&error];
if (!error) {
NSString *json = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
return json;
}
}
return nil;
}
28.将数组对象转换为 JSON 字符串
+ (NSString *)jsonPrettyStringEncoded:(NSArray *)array{
if ([NSJSONSerialization isValidJSONObject:array]) {
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:array options:NSJSONWritingPrettyPrinted error:&error];
if (!error) {
NSString *json = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
return json;
}
}
return nil;
}
29. 获取 WiFi 信息
需要引入头文件:
#import <SystemConfiguration/CaptiveNetwork.h>
代码:
//获取 WiFi 信息
- (NSDictionary *)fetchSSIDInfo {
NSArray *ifs = (__bridge_transfer NSArray *)CNCopySupportedInterfaces();
if (!ifs) {
return nil;
}
NSDictionary *info = nil;
for (NSString *ifnam in ifs) {
info = (__bridge_transfer NSDictionary *)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
if (info && [info count]) { break; }
}
return info;
}
30. 获取广播地址、本机地址、子网掩码、端口信息
需要引入头文件:
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Menlo; color: #ff4647}span.s1 {font-variant-ligatures: no-common-ligatures; color: #eb905a}span.s2 {font-variant-ligatures: no-common-ligatures}
#import <ifaddrs.h>
#import <arpa/inet.h>
//获取广播地址、本机地址、子网掩码、端口信息
- (NSMutableDictionary *)getLocalInfoForCurrentWiFi {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
struct ifaddrs *interfaces = NULL;
struct ifaddrs *temp_addr = NULL;
int success = 0;
// retrieve the current interfaces - returns 0 on success
success = getifaddrs(&interfaces);
if (success == 0) {
// Loop through linked list of interfaces
temp_addr = interfaces;
//*/
while(temp_addr != NULL) {
if(temp_addr->ifa_addr->sa_family == AF_INET) {
// Check if interface is en0 which is the wifi connection on the iPhone
if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
//广播地址
NSString *broadcast = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)];
if (broadcast) {
[dict setObject:broadcast forKey:@"broadcast"];
}
// NSLog(@"broadcast address--%@",broadcast);
//本机地址
NSString *localIp = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
if (localIp) {
[dict setObject:localIp forKey:@"localIp"];
}
// NSLog(@"local device ip--%@",localIp);
//子网掩码地址
NSString *netmask = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_netmask)->sin_addr)];
if (netmask) {
[dict setObject:netmask forKey:@"netmask"];
}
// NSLog(@"netmask--%@",netmask);
//--en0 端口地址
NSString *interface = [NSString stringWithUTF8String:temp_addr->ifa_name];
if (interface) {
[dict setObject:interface forKey:@"interface"];
}
// NSLog(@"interface--%@",interface);
return dict;
}
}
temp_addr = temp_addr->ifa_next;
}
}
// Free memory
freeifaddrs(interfaces);
return dict;
}
