swift学习笔记

1..取视频第一帧
- (void)movieToImage{
    NSURL *url = self.playerView.videoURL;
    
    AVURLAsset *asset=[[AVURLAsset alloc] initWithURL:url options:nil];
    AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    generator.appliesPreferredTrackTransform=TRUE;
    CMTime thumbTime = CMTimeMakeWithSeconds(0,30);
    
    AVAssetImageGeneratorCompletionHandler handler =
    ^(CMTime requestedTime, CGImageRef im, CMTime actualTime, AVAssetImageGeneratorResult result, NSError *error){
        if (result != AVAssetImageGeneratorSucceeded) {       }//没成功
        
        UIImage *thumbImg = [UIImage imageWithCGImage:im];
        
        [self performSelectorOnMainThread:@selector(movieImage:) withObject:thumbImg waitUntilDone:YES];
        
    };
    
    generator.maximumSize = self.playerView.size;
    [generator generateCGImagesAsynchronouslyForTimes:
     [NSArray arrayWithObject:[NSValue valueWithCMTime:thumbTime]] completionHandler:handler];
 
}

2..判断一个对象是否是某个类

if Vc.isKind(of: GLHomeTableViewController.self) {
            
            return true
        }

3..获取控件的最大值

CGRect.init().maxY

4..打包需要修改

70665009-32E6-4330-AF3B-29658BCF2D17.png

5..归结档

var path = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).last! + "/user.data"

class GLAccountModel: NSObject {

    //姓名
    var name: String?
    
    //构造函数
    init(dic: [String: Any?]) {
        super.init()
        setValuesForKeys(dic)
    }
    
    //kvc赋值
    override func setValue(_ value: Any?, forKey key: String) {
        super.setValue(value, forKey: key)
    }
    
    //防止崩溃
    override func setValue(_ value: Any?, forUndefinedKey key: String) {
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init()
        
        self.name = aDecoder.decodeObject(forKey: "name") as? String
       
        
    }
    
    func encode(with aCoder: NSCoder) {
    
        aCoder.encode(self.name, forKey: "name")
                
    }
    
    class func save(user: GLAccountModel) -> Bool {
        return NSKeyedArchiver.archiveRootObject(user, toFile: path)
    }
    
    class func account() -> GLAccountModel? {
        return NSKeyedUnarchiver.unarchiveObject(withFile: path) as? GLAccountModel
    }
    
}

6..Swift中 deinit 可以实现 “dealloc” 的功能

deinit {
        println("没有循环引用")
    }