iOS ---OC中的小知识点(1)

1.缓存路径下文件大小

- (unsigned long long int) cacheFolderSize {
    NSFileManager  *_manager = [NSFileManager defaultManager];
    NSArray *_cachePaths =  NSSearchPathForDirectoriesInDomains(NSCachesDirectory,
                                                NSUserDomainMask, YES);
    NSString  *_cacheDirectory = [_cachePaths objectAtIndex:]; 
    NSArray  *_cacheFileList;
    NSEnumerator *_cacheEnumerator;
    NSString *_cacheFilePath;
    unsigned long long int _cacheFolderSize = ;
    _cacheFileList = [ _manager subpathsAtPath:_cacheDirectory];
   _cacheEnumerator = [_cacheFileList objectEnumerator];
    while (_cacheFilePath = [_cacheEnumerator nextObject]) {
         NSDictionary *_cacheFileAttributes = [_managerfileAttributesAtPath:  
         [_cacheDirectory   stringByAppendingPathComponent:_cacheFilePath]
         traverseLink:YES];
      _cacheFolderSize += [_cacheFileAttributes fileSize];
    }
// 单位是字节
    return _cacheFolderSize;
}

2.Popover push 时 Frame无法改变解决办法

在popover中的ViewController中实现：

- (void)viewWillAppear:(BOOL)animated 
{
   CGSize size = CGSizeMake(320, 480); // size of view in popover  
   self.contentSizeForViewInPopover = size; 
   [super viewWillAppear:animated]; 
}

3.SFHFKeychainUtils 存储信息

苹果SDK自带的就有密码保护，使用方法很简单，如下：
1、引入Security.frameWork框架。
2、引入头文件：SFHKeychainUtils.h.
3、存密码：

[SFHFKeychainUtils storeUsername:@"dd" andPassword:@"aa"forServiceName:SERVICE_NAMEupdateExisting:1 error:nil];
[SFHFKeychainUtils deleteItemForUsername:@"dd" andServiceName:SERVICE_NAME error:nil];

4、取密码：

NSString *passWord =  [SFHFKeychainUtils getPasswordForUsername:@"dd"andServiceName:SERVICE_NAMEerror:nil];

4.missing required architecture i386 in file 解决办法

在TargetInfo里面修改 Framework Search Pasths 删除里面内容就可以了。

5.view 放大缩小动画效果

//创建缩小了的视图
myWeiBoImageVC = [[UIViewController alloc] init];
myWeiBoImageVC.view.clipsToBounds = YES;
myWeiBoImageVC.view.alpha = 0.0;
myWeiBoImageVC.view.frame = CGRectMake(64, 0, 1024-64, 768-20);
[self.view addSubview:myWeiBoImageVC.view];
    
CGAffineTransform newTransform = 
CGAffineTransformScale(myWeiBoImageVC.view.transform, 0.1, 0.1);
[myWeiBoImageVC.view setTransform:newTransform];
myWeiBoImageVC.view.center = CGPointMake(670, 100);
[self performSelector:@selector(imageViewControllerBigAnimation)];

//放大刚刚创建缩小后的视图
- (void)imageViewControllerBigAnimation{
    [UIView beginAnimations:@"imageViewBig" context:nil];
    [UIView setAnimationDuration:0.5];   
    CGAffineTransform newTransform =            CGAffineTransformConcat(myWeiBoImageVC.view.transform,  CGAffineTransformInvert(myWeiBoImageVC.view.transform));
    [myWeiBoImageVC.view setTransform:newTransform];
    myWeiBoImageVC.view.alpha = 1.0;
    myWeiBoImageVC.view.center = CGPointMake(416, 510)；
    [UIView commitAnimations];
}

//缩小视图 隐藏
- (void)imageViewControllerSmallAnimation{
    [UIView beginAnimations:@"imageViewSmall" context:nil];
    [UIView setAnimationDuration:0.5];
    CGAffineTransform newTransform =  CGAffineTransformScale(myWeiBoImageVC.view.transform, 0.1, 0.1);
    [myWeiBoImageVC.view setTransform:newTransform];
    myWeiBoImageVC.view.center = CGPointMake(670, 100);
    [UIView commitAnimations];
}

6.UIScrollView 控制View缩放

allImageScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 768, 1024)];
allImageScrollView.minimumZoomScale = 0.3;
allImageScrollView.maximumZoomScale = 1.0;
allImageScrollView.backgroundColor = [UIColor clearColor];
allImageScrollView.delegate = self;
[self.view addSubview:allImageScrollView];

mPicStatusesViewController = [[PicStatusesViewController alloc] init];
[allImageScrollView addSubview:mPicStatusesViewController.view];

//UIScrollView Delegete 实现

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return mPicStatusesViewController.view; //返回ScrollView上添加的需要缩放的视图
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView
{
    //缩放操作中被调用
}

- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale
{
    //缩放结束后被调用
  }

7.iOS3.2 播放视频

NSString *urlString = [NSString stringWithString:@"视频url"];
NSURL *movieUrl = [[NSURL alloc] initWithString:urlString];
    
MPMoviePlayerController *myMoviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:movieUrl];
myMoviePlayer.view.frame = CGRectMake(250, 250, 350, 350);
[self.view addSubview:myMoviePlayer.view];    
myMoviePlayer.shouldAutoplay = YES;
myMoviePlayer.scalingMode= MPMovieScalingModeAspectFit;  
[myMoviePlayer play];

8.给View添加阴影 和边框

UIImageView *imgvPhoto  = [UIImageView alloc] init];

//添加边框
   CALayer *layer = [_imgvPhoto layer];
    layer.borderColor = [[UIColor whiteColor] CGColor];
    layer.borderWidth = 5.0f;
//添加四个边阴影
    _imgvPhoto.layer.shadowColor = [UIColor blackColor].CGColor;
    _imgvPhoto.layer.shadowOffset = CGSizeMake(0, 0);
    _imgvPhoto.layer.shadowOpacity = 0.5;
    _imgvPhoto.layer.shadowRadius = 10.0;
//添加两个边阴影
    _imgvPhoto.layer.shadowColor = [UIColor blackColor].CGColor;
    _imgvPhoto.layer.shadowOffset = CGSizeMake(4, 4);
    _imgvPhoto.layer.shadowOpacity = 0.5;
    _imgvPhoto.layer.shadowRadius = 2.0;

9.使用NSTimer与UIView动画实现飘雪效果

viewDidLoad事件中，增加一个图片及定时器并启动,这里的pic请在头文件中定义。
-(void)viewDidLoad{
 [super viewDidLoad];
 self.pic = [UIImage imageNamed:@"snow.png"];//初始化图片
 //启动定时器，实现飘雪效果
 [NSTimer scheduledTimerWithTimeInterval:(0.2) target:self selector:@selector(ontime) userInfo:nil repeats:YES];
}
然后再实现定时器定时调用的ontime方法：
-(void)ontime{
 UIImageView *view = [[UIImageView alloc] initWithImage:pic];//声明一个UIImageView对象，用来添加图片
 view.alpha = 0.5;//设置该view的alpha为0.5，半透明的
 int x = round(random()20);//随机得到该图片的x坐标
 int y = round(random()20);//这个是该图片移动的最后坐标x轴的
 int s = round(random())+10;//这个是定义雪花图片的大小
 int sp = 1/round(random()0)+1;//这个是速度
 view.frame = CGRectMake(x, -50, s, s);//雪花开始的大小和位置
 [self.view addSubview:view];//添加该view
 [UIView beginAnimations:nil context:view];//开始动画
 [UIView setAnimationDuration:10*sp];//设定速度
 view.frame = CGRectMake(y, 500, s, s);//设定该雪花最后的消失坐标
 [UIView setAnimationDelegate:self];
 [UIView commitAnimations];
}

10.配置Xcode 看程序崩溃信息

1、在xcode中的左侧目录中找到Executables 打开
2、双击和工程名一样的文件。
3、在打开的文件中的Arguments选项，在下面的框中加入Name： NSZombieEnabled 设置value为YES。