Question

我想为我的应用做一个实时相机预览，但是当我在我的设备上运行应用时，它会崩溃。我写了一些代码，实际上，我认为，这些代码必须有效。

@synthesize vImagePreview;

-(void)viewDidLoad {

    [super viewDidLoad];

}

- (void)viewDidUnLoad {
    [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        vImagePreview = nil;
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];



    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];

    [session startRunning];
}

我创建了一个UIView并将其链接到vImagePreview，但它仍然无效...... 它正在崩溃：

2013-12-21 13:22:09.086 UnknownApp[1862:60b] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIApplication 0x13f500230> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key vImagePreview.'

Answer 1

您无法在UIView上捕获视频预览，您需要UIImageView来呈现视频捕获预览。

将vImagePreview类型更改为UIImageView，如下所示

@property(nonatomic, retain) IBOutlet UIImageView *vImagePreview;

相机实时预览不起作用，SIGABRT

1 个答案: