ios - 从 ViewController 取图片

Question

我正在制作一个带有 ScrollView 的应用程序。在一个屏幕上，我有很多 UIPopover。当您将页面滚动到新屏幕时，我希望能够在按下按钮后立即拍照。 目前我有一个启动相机的按钮和一个添加为子层的预览层

代码:

- (IBAction)startCameraButtonPushed:(id)sender
{
    if (session.isRunning) {
        [startCamera setTitle:@"Start Camera" forState:UIControlStateNormal];
        previewLayer.hidden = YES;
        [session stopRunning];
        session = nil;
        previewLayer = nil;
    } else {
        [startCamera setTitle:@"Stop Camera" forState:UIControlStateNormal];
        session = [[AVCaptureSession alloc] init];
        AVCaptureOutput *output = [[AVCaptureStillImageOutput alloc] init];
        [session addOutput:output];
        NSArray *possibleDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
        AVCaptureDevice *device = [possibleDevices objectAtIndex:0];
        NSError *error = nil;
        AVCaptureDeviceInput* input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
        session.sessionPreset = AVCaptureSessionPresetPhoto;

        [session addInput:input];

        previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session];

        previewLayer.frame = CGRectMake(3202, 100, 800, 400);
        previewLayer.hidden = YES;
        // previewLayer.delegate = self;
        [self.scrollView.layer addSublayer:previewLayer];
        previewLayer.hidden = NO;
        [session startRunning];
    }

}

如您所见，相机处于人像模式，我非常努力地让它变成风景模式。到目前为止没有运气。还很难找到一个按钮来实际拍照。 如果有人能帮我一点忙，我将不胜感激!

Answer 1

您可以转换预览层以使视频以正确的方向显示:

if (self.interfaceOrientation == UIInterfaceOrientationPortrait) {
    previewLayer.affineTransform = CGAffineTransformMakeRotation(0);
} else if (self.interfaceOrientation == UIInterfaceOrientationLandscapeLeft) {
    previewLayer.affineTransform = CGAffineTransformMakeRotation(M_PI/2);
} else if (self.interfaceOrientation == UIInterfaceOrientationLandscapeRight) {
    previewLayer.affineTransform = CGAffineTransformMakeRotation(-M_PI/2);
} else if (self.interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
    previewLayer.affineTransform = CGAffineTransformMakeRotation(M_PI);
}