objective-c – UIImagePickerController的快门

我有UI ImagePickerController的错误,其源类型是相机.有时控制器出现后,快门没有打开,我无法看到相机视频信号,但拍摄的照片是正确的.

可能是我做错了什么？码：

if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera]){

            UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
            cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;
            cameraUI.allowsEditing = NO;
            cameraUI.showsCameraControls = NO;
            cameraUI.delegate = self;

            NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:@"OverlayView" owner:self options:nil];
            UIView *controlsView = [nibObjects objectAtIndex:0];

            CGRect overlayViewFrame = cameraUI.cameraOverlayView.frame;
            CGRect controlsFrame = CGRectMake(0.0,CGRectGetHeight(overlayViewFrame) - 54.0,CGRectGetWidth(overlayViewFrame),54.0);

            controlsView.frame = controlsFrame;
            [cameraUI.cameraOverlayView addSubview:controlsView];

            [self presentModalViewController: cameraUI animated: YES];            
    }

解决方法

在锁定/解锁应用程序后,我发生了同样的情况,看起来快门在viewDidAppear上打开.

所以,我将我的父视图控制器订阅到UIApplicationDidBecomeActiveNotification并手动重新执行包含UIImagePickerController的控制器的viewWillAppear和viewDidAppear方法

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(applicationBecomeActive)
                                             name:UIApplicationDidBecomeActiveNotification
                                           object:nil];

.
. 
.

- (void)applicationBecomeActive {
    if (imagePicker_)
        [imagePicker_ openShutter];
}

然后在包含UIImagePickerController的控制器上

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [imagePickerController_ viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [imagePickerController_ viewDidAppear:animated];
    imagePickerController_.cameraFlashMode = cameraFlashMode_;
    imagePickerController_.cameraDevice = cameraDevice_;
}
- (void)openShutter {
    [imagePickerController_ viewWillAppear:YES];
    [imagePickerController_ viewDidAppear:YES];
}

PS：如果你试试这个,不要忘记删除观察者

[[NSNotificationCenter defaultCenter] removeObserver:self];

希望这可以帮助