Objective-C 笔记

记录一些 Objective-C 的实用代码片段，本篇属于个人笔记

常用关键字一览

@interface、@implementation、@end 
@public、@protected、@private、@selector 
@try、@catch、@throw、@finally 
@protocol、@optional、@required、@class
@property、@synthesize、@dynamic
BOOL Class SEL YES NO id self super nil atomic nonatomic retain assign copy block …

方法调用 基础语法

#import <Foundation/Foundation.h>
 
// - 表示动态方方法
// ＋表示静态方法
@interface TestClass : NSObject
{
@public
    //下划线开头
    NSString * _name;
    int _age;
}
 
@property NSString * NickName;
 
+(void) staticSayHello;
-(void) SayHello;
 
+(double) staticTestWithParams:(int) num ThisIsWord:(int) num2;
 
@end
 
//实现上文中的方法才可以调用
@implementation TestClass
 
//实现构造函数
-(id)init
{
    if (self = [super init]) {
        NSLog(@"初始化构造函数...");
    }
    returnself;
}
-(id)initWithNickname:(NSString*)nickName
{
    if (self = [super init]) {
        NSLog(@"带有参数的构造 %@",nickName);
    }
    returnself;
}
-(id)initAgeAndNickname:(int)age andName :(NSString*)name
{
    if (self =[super init]) {
        NSLog(@"带有双参数的构造 %d +++ %@",age,name);
    }
    returnself;
}
 
 
-(void) SayHello
{
    NSLog(@"Name is %@ and age is %d",_name,_age);
}
+(void)staticSayHello{
    NSLog(@"Static Call SayHello must call by Class ..");
}
+(double)staticTestWithParams:(int)num ThisIsWord:(int) num2
{
    NSLog(@"%d +========+++=%d",num,num2);
    return num;
}
@end
 
int main(int argc, const char * argv[]) {
    
    TestClass* test = [[TestClassalloc] initAgeAndNickname:21andName:@"xiaonian"];
    
    test->_name = @"Hello World";
    test->_age = 21;
    
    [test SayHello];//Call Method
    [TestClassstaticSayHello];//Casll Static Method
    [TestClassstaticTestWithParams:123456ThisIsWord:890123];
    
    NSLog(@"--------分隔符---------");
    
    Class c = [TestClass class];
    NSLog(@"%p",c);
    //0x100004708
    
    NSLog(@"--------分隔符-@SEL--------");
    SEL sel = @selector(SayHello);
    [test performSelector:sel];
    [test performSelector:@selector(SayHello)];
    if ([test respondsToSelector:sel]) {
        NSLog(@"%@",@"可以相应sel－－sayhello");
    }
    NSLog(@"--------分隔符-@property--------");
    
    [test setNickName:@"xiaonian"];
    NSString* nickName = [test NickName];
    test.NickName = @"xiaonian2";
    NSString* nickName2 = test.NickName;
    NSLog(@"%@ and %@",nickName,nickName2);
    
    return 0;
}

基础类型转换

int hours = floor(rawtime / 3600000);

int mins = floor((rawtime % 3600000) / (1000 * 60));
int secs = floor(((rawtime % 3600000) % (1000 * 60)) / 1000);

NSLog(@"%d:%d:%d", hours, mins, secs);

NSString *hoursStr = [NSString stringWithFormat:@"%d", hours];
NSString *minsStr = [NSString stringWithFormat:@"%d", mins];
NSString *secsStr = [NSString stringWithFormat:@"%d", secs];

NSLog(@"%a:%a:%a", hoursStr, minsStr, secsStr);

参考链接 int to NSString

获取设备当前网络IP地址

//获取设备当前网络IP地址
- (NSString *)getIPAddress:(BOOL)preferIPv4
{
    NSArray *searchArray = preferIPv4 ?
    @[ /*IOS_VPN @"/" IP_ADDR_IPv4, IOS_VPN @"/" IP_ADDR_IPv6,*/ IOS_WIFI @"/" IP_ADDR_IPv4, IOS_WIFI @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6 ] :
    @[ /*IOS_VPN @"/" IP_ADDR_IPv6, IOS_VPN @"/" IP_ADDR_IPv4,*/ IOS_WIFI @"/" IP_ADDR_IPv6, IOS_WIFI @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4 ] ;
    
    NSDictionary *addresses = [self getIPAddresses];
    NSLog(@"addresses: %@", addresses);
    
    __block NSString *address;
    [searchArray enumerateObjectsUsingBlock:^(NSString *key, NSUInteger idx, BOOL *stop)
     {
         address = addresses[key];
         if(address) *stop = YES;
     } ];
    return address ? address : @"0.0.0.0";
}

//获取所有相关IP信息
- (NSDictionary *)getIPAddresses
{
    NSMutableDictionary *addresses = [NSMutableDictionary dictionaryWithCapacity:8];
    
    // retrieve the current interfaces - returns 0 on success
    struct ifaddrs *interfaces;
    if(!getifaddrs(&interfaces)) {
        // Loop through linked list of interfaces
        struct ifaddrs *interface;
        for(interface=interfaces; interface; interface=interface->ifa_next) {
            if(!(interface->ifa_flags & IFF_UP) /* || (interface->ifa_flags & IFF_LOOPBACK) */ ) {
                continue; // deeply nested code harder to read
            }
            const struct sockaddr_in *addr = (const struct sockaddr_in*)interface->ifa_addr;
            char addrBuf[ MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) ];
            if(addr && (addr->sin_family==AF_INET || addr->sin_family==AF_INET6)) {
                NSString *name = [NSString stringWithUTF8String:interface->ifa_name];
                NSString *type;
                if(addr->sin_family == AF_INET) {
                    if(inet_ntop(AF_INET, &addr->sin_addr, addrBuf, INET_ADDRSTRLEN)) {
                        type = IP_ADDR_IPv4;
                    }
                } else {
                    const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6*)interface->ifa_addr;
                    if(inet_ntop(AF_INET6, &addr6->sin6_addr, addrBuf, INET6_ADDRSTRLEN)) {
                        type = IP_ADDR_IPv6;
                    }
                }
                if(type) {
                    NSString *key = [NSString stringWithFormat:@"%@/%@", name, type];
                    addresses[key] = [NSString stringWithUTF8String:addrBuf];
                }
            }
        }
        // Free memory
        freeifaddrs(interfaces);
    }
    return [addresses count] ? addresses : nil;
}