iOS 常用的代码片段

（1）多个按钮实现单选

-(void)btnPressed:(UIButton *)btn
{
    for (int i = 0; i < 3; i++)
    {
        UIButton *button = (UIButton *)[[btn superview]viewWithTag:1000 + i];
        [button setSelected:NO];
        [button setTitleColor:SUBMIT_PAY_NUM_COLOR forState:UIControlStateNormal];
        
    }
    self.Selectbutton = (UIButton *)btn;
    [self.Selectbutton setSelected:YES];
    [self.Selectbutton setTitleColor:[UIColor colorWithHexString:@"0xfdd000"] forState:UIControlStateNormal];

}

（2）获取设备IP地址

// 获取设备IP地址
-(NSString *)getIPAddress {
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    // 检索当前接口,在成功时,返回0
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // 循环链表的接口
        temp_addr = interfaces;
        while(temp_addr != NULL) {
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                // 检查接口是否en0 wifi连接在iPhone上
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
                    // 得到NSString从C字符串
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    // 释放内存
    freeifaddrs(interfaces);
    return address;
}

（3）MD5加密

+ (NSString *)MD5:(NSString *)string{
    
    const char* input = [string UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(input, (CC_LONG)strlen(input), result);
    
    NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    for (NSInteger i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
        [digest appendFormat:@"%02x", result[i]];
    }
    return digest;
}

（4）获取父控制器

id object = [self nextResponder];
    while (![object isKindOfClass:[UIViewController class]] && object != nil) {
        object = [object nextResponder];
    }
    UIViewController *superController = (UIViewController*)object;

（5）打印Model每个字段值

- (NSString *)description {
    //初始化一个字典
    NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];

    //得到当前class的所有属性
    uint count;
    objc_property_t *properties = class_copyPropertyList([self class], &count);

    //循环并用KVC得到每个属性的值
    for (int i = 0; i<count; i++) {
        objc_property_t property = properties[i];
        NSString *name = @(property_getName(property));
        id value = [self valueForKey:name]?:@"nil";//默认值为nil字符串
        [dictionary setObject:value forKey:name];//装载到字典里
    }
    //释放
    free(properties);
    //return
    return [NSString stringWithFormat:@"<%@: %p> -- %@",[self class],self,dictionary];
}

（6）UIButton设置:图片在上，文字在下

//图片在上，文字在下
- (void)setButtonImageAndTitleWithSpace:(CGFloat)spacing WithButton:(UIButton *)btn{
    CGSize imageSize = btn.imageView.frame.size;
    CGSize titleSize = btn.titleLabel.frame.size;
    CGSize textSize = [btn.titleLabel.text sizeWithFont:btn.titleLabel.font];
    CGSize frameSize = CGSizeMake(ceilf(textSize.width), ceilf(textSize.height));
    if (titleSize.width + 0.5 < frameSize.width) {
        titleSize.width = frameSize.width;
    }
    CGFloat totalHeight = (imageSize.height + titleSize.height + spacing);
    btn.imageEdgeInsets = UIEdgeInsetsMake(- (totalHeight - imageSize.height), 0.0, 0.0, - titleSize.width);
    btn.titleEdgeInsets = UIEdgeInsetsMake(0, - imageSize.width, - (totalHeight - titleSize.height), 0);
}

（7）数组是否为空

if (self.selectedModelArray != nil && ![self.selectedModelArray isKindOfClass:[NSNull class]] && self.selectedModelArray.count != 0)

（8）是否包含某个字符串

-(NSMutableString *)stringRang:(NSString *)str
{
    NSRange range;
    range = [str rangeOfString:@"amp;"];
    NSMutableString *resultString  = [NSMutableString string];
    if (range.location != NSNotFound)
    {
        NSLog(@"found at location = %lu, length = %lu",(unsigned long)range.location,(unsigned long)range.length);
        NSString *app_id = [str substringToIndex:range.location];
        NSString *biz_content = [str substringFromIndex:range.location + range.length];
        resultString = [app_id stringByAppendingString:biz_content];
    }
    else
    {
        NSLog(@"Not Found");
    }
    return resultString;
}