向AVCam添加UICollectionView覆盖

Question

所以我有一个用来拍照的AVCamViewController。背景是实时图像馈送，覆盖在顶部的是用于拍摄照片的按钮和用于显示拍摄的照片的UIImageView。这两种方法都有效。我想有一个侧滚collectionView来显示所有拍摄的照片，但我似乎不能添加collectionView到覆盖视图，即使添加按钮和UIImageView没有问题。以下是视图控制器的视图did加载方法的实现代码：

- (void)viewDidLoad {


_imagesTaken = [[NSMutableArray alloc] init];

_vImagePreview = [[UIView alloc] initWithFrame:self.view.bounds];
_vImage = [[UIImageView alloc] initWithFrame:CGRectMake(50, 50, 50, 50)];

UIButton *shutter = [[UIButton alloc] initWithFrame:CGRectMake(100,500,50,50)];
[shutter addTarget:self action:@selector(takePicture) forControlEvents:UIControlEventTouchUpInside];
[shutter setBackgroundColor:[UIColor greenColor]];

[_vImagePreview addSubview:shutter];
[_vImagePreview addSubview:_vImage];



UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];
[layout setItemSize:CGSizeMake(50, 50)];

_collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(10, 400, 315, 60) collectionViewLayout:layout];
_collectionView.backgroundColor = [UIColor redColor];
_collectionView.pagingEnabled = YES;
_collectionView.delegate = self;
_collectionView.dataSource = self;
//[_collectionView setDataSource:self];
//[_collectionView setDelegate:self];

[_collectionView registerClass:[PhotoCell class] forCellWithReuseIdentifier:@"cellIdentifier"];

[_vImagePreview addSubview:_collectionView];
[_collectionView reloadData];

[self.view addSubview:_vImagePreview];

[super viewDidLoad];

AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetMedium;

//CALayer *viewLayer = self.vImagePreview.layer;
//NSLog(@"viewLayer = %@", viewLayer);

AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

captureVideoPreviewLayer.frame = self.vImagePreview.bounds;
[self.vImagePreview.layer addSublayer:captureVideoPreviewLayer];

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
    // Handle the error appropriately.
    NSLog(@"ERROR: trying to open camera: %@", error);
}
[session addInput:input];

_stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
[_stillImageOutput setOutputSettings:outputSettings];
[session addOutput:_stillImageOutput];

[session startRunning];

}

你知道为什么按钮和UIImageView会出现，而collectionView却没有吗？

下面是我的头文件：

#import <UIKit/UIKit.h>
#import "CaptureSessionManager.h"

@interface AVOverlayViewController : UIViewController <UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>

@property (retain) CaptureSessionManager *captureManager;
@property (nonatomic, strong) UILabel *scanningLabel;
@property (nonatomic, strong) NSMutableArray *imagesTaken;

@property(nonatomic, retain) AVCaptureStillImageOutput *stillImageOutput;
@property(nonatomic, retain) IBOutlet UIView *vImagePreview;
@property(nonatomic, retain) IBOutlet UIImageView *vImage;
@property (nonatomic, retain) IBOutlet UICollectionView *collectionView;



@end

另外，这些是我在ViewController的实现文件中调用的委托方法：

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
    return [_imagesTaken count];
    NSLog(@"%d added to collection view",[_imagesTaken count]);
}


    - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{

        PhotoCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"PhotoCellIdentifier" forIndexPath:indexPath];

        UIImage *fromCamera = [_imagesTaken objectAtIndex:indexPath.row];

        [[cell imageView] setImage:fromCamera];

        cell.backgroundColor=[UIColor greenColor];

        return cell;
    }

这两个委托方法都不会被调用。任何帮助都是非常感谢的！谢谢!

Answer 1

collectionView是@属性有什么原因吗？为什么不实现像这样的东西：

@interface AVOverlayViewController : UIViewController <UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>
{
    UICollectionView *collectionView;
}

如果这样还不能解决问题，您可以尝试(而不是在viewDidLoad中设置大小)在委托中实现- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath。

我也会说从小的开始，先加载细胞，看看你是否能让它工作。然后，一旦您确定集合已正确实现，就可以添加所需的图像。我会从加载空白的绿色单元格开始，然后可能会将集合视图的背景颜色设置为一些明显的颜色。