iOS - 自定义相机取景框

    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

    imagePicker.delegate = self;

    imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;//获取类型是摄像头，还可以是相册

    imagePicker.modalTransitionStyle = UIModalTransitionStyleCoverVertical;

    imagePicker.allowsEditing = NO;//如果为NO照出来的照片是原图，比如4s和5的iPhone出来的尺寸应该是（2000+）*（3000+），差不多800W像素，如果是YES会有个选择区域的方形方框

//    imagePicker.showsCameraControls = NO;//默认是打开的这样才有拍照键，前后摄像头切换的控制，一半设置为NO的时候用于自定义ovelay

//    UIImageView *overLayImg = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 640)];
//    overLayImg.image = [UIImage imageNamed:@"overlay.png"];

//    imagePicker.cameraOverlayView = overLayImg;//3.0以后可以直接设置cameraOverlayView为overlay
//    imagePicker.wantsFullScreenLayout = YES;

    [self presentModalViewController:imagePicker animated:YES];