iOS知识点总结

1.监测网络状态：

- (void)checkNetwork {
    __block NSString *tips;
    _reachiabilityManager = [AFNetworkReachabilityManager manager];
    [_reachiabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
            case -1:{
                tips = @"未知网络错误";
                break;
            }
            case 0:{
                tips = @"暂无网络，请检查网络";
                break;
            }
            case 1:{
                tips = @"当前连接的数据流量";
                break;
            }
            case 2:{
                tips = @"当前连接的是wifi";
                break;
            }
            default:
                break;
        }
        if (tips.length) {
            // 提示
        }
    }];
    [_reachiabilityManager startMonitoring];
}

2.进入直播页面判断权限：

// 判断是否是模拟器
        if ([[UIDevice currentDevice] isSimulator]) {
            [self showNoticeMessage:@"请使用真机运行"];
            return NO;
        }
        
        // 判断是否有摄像头
        if(![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
            [self showNoticeMessage:@"您的设备没有摄像头或者相关的驱动, 不能进行直播"];
            return NO;
        }
        
        // 判断是否有摄像头权限
        AVAuthorizationStatus  authorizationStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        if (authorizationStatus == AVAuthorizationStatusRestricted|| authorizationStatus == AVAuthorizationStatusDenied) {
            [self showNoticeMessage:@"app需要访问您的摄像头。
请启用摄像头-设置/隐私/摄像头"];
            return NO;
        }
        
        // 开启麦克风权限
        AVAudioSession *audioSession = [AVAudioSession sharedInstance];
        if ([audioSession respondsToSelector:@selector(requestRecordPermission:)]) {
            [audioSession performSelector:@selector(requestRecordPermission:) withObject:^(BOOL granted) {
                if (granted) {
                    return YES;
                } else {
                    [self showNoticeMessage:@"app需要访问您的麦克风。
请启用麦克风-设置/隐私/麦克风"];
                    return NO;
                }
            }];
        }

3.直播使用的第三方：

视频播放：IJKMediaFramework

弹幕：BarrageRenderer

推流：LFLiveKit

源码学习： https://github.com/SunLiner/MiaowShow

4.Cell中的倒计时：

/// 每秒执行一次
- (void)countDownWithPER_SECBlock:(void (^)())PER_SECBlock {
    
    if (_timer==nil) {
        dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
        _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
        dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行
        dispatch_source_set_event_handler(_timer, ^{
            dispatch_async(dispatch_get_main_queue(), ^{
                PER_SECBlock();
            });
        });
        dispatch_resume(_timer);
    }
}

5.搜索时设置“搜索高亮”：

 // 设置搜索高亮
    if (model.searchKeyWord.length > 0) {
        // 从全部文字中找到特殊的文字
        NSRange range = [model.titleStr rangeOfString:model.searchKeyWord];
        if (range.location != NSNotFound && range.length > 0) {
            NSMutableAttributedString *muAttStr = [[NSMutableAttributedString alloc] initWithString:model.titleStr];
            [muAttStr addAttribute:NSForegroundColorAttributeName value:BLUE_COLOR range:range];
            self.titleLabel.attributedText = muAttStr;
        }
        
    }