uiImagePickerController不填充屏幕

相机的纵横比为4:3,屏幕的纵横比为3:2。所以,除非你愿意裁剪到3:2,否则相机图片根本无法填充屏幕。为此,请应用适当的比例变换。

按固定值缩放不是个好主意…我敢肯定,在这里使用公认答案的人可能会在iPhone5推出时发现答案。

下面是一个代码片段,根据屏幕分辨率动态缩放,以消除字母装箱。

// Device's screen size (ignoring rotation intentionally):
CGSize screenSize = [[UIScreen mainScreen] bounds].size;

// iOS is going to calculate a size which constrains the 4:3 aspect ratio
// to the screen size. We're basically mimicking that here to determine
// what size the system will likely display the image at on screen.
// NOTE: screenSize.width may seem odd in this calculation - but, remember,
// the devices only take 4:3 images when they are oriented *sideways*.
float cameraAspectRatio = 4.0 / 3.0;
float imageWidth = floorf(screenSize.width * cameraAspectRatio);
float scale = ceilf((screenSize.height / imageWidth) * 10.0) / 10.0;

self.ipc.cameraViewTransform = CGAffineTransformMakeScale(scale, scale);

嘿,我看到一些人在计算完iPhone5的比例后,仍然在底部得到黑条。我有一段时间遇到了这个问题,但后来我发现你必须转换视图,使其位于屏幕中间,然后应用比例。这是我做这两件事的代码,对我有用!

    CGSize screenBounds = [UIScreen mainScreen].bounds.size;

    CGFloat cameraAspectRatio = 4.0f/3.0f;

    CGFloat camViewHeight = screenBounds.width * cameraAspectRatio;
    CGFloat scale = screenBounds.height / camViewHeight;

    m_imagePickerController.cameraViewTransform = CGAffineTransformMakeTranslation(0, (screenBounds.height - camViewHeight) / 2.0);
    m_imagePickerController.cameraViewTransform = CGAffineTransformScale(m_imagePickerController.cameraViewTransform, scale, scale);

用这个转换它:

#define CAMERA_TRANSFORM                    1.12412

_picker.wantsFullScreenLayout = YES;
_picker.cameraViewTransform = CGAffineTransformScale(_picker.cameraViewTransform, CAMERA_TRANSFORM, CAMERA_TRANSFORM);

从我在iOS 7、iPhone 5S上的经验来看,要将图片的中心显示为全屏预览,您必须连接转换,而不是按顺序进行转换:

pickerController.cameraOverlayView = self.view;

CGSize screenSize = [[UIScreen mainScreen] bounds].size;   // 320 x 568

float scale = screenSize.height / screenSize.width*3/4;  // screen height divided by the pickerController height ... or:  568 / ( 320*4/3 )

CGAffineTransform translate=CGAffineTransformMakeTranslation(0,(screenSize.height - screenSize.width*4/3)*0.5);
CGAffineTransform fullScreen=CGAffineTransformMakeScale(scale, scale);
pickerController.cameraViewTransform =CGAffineTransformConcat(fullScreen, translate);

答案就在这里。

let screenSize:CGSize = UIScreen.mainScreen().bounds.size

let ratio:CGFloat = 4.0 / 3.0
let cameraHeight:CGFloat = screenSize.width * ratio
let scale:CGFloat = screenSize.height / cameraHeight

let imag:UIImagePickerController = UIImagePickerController()
imag.cameraViewTransform = CGAffineTransformMakeTranslation(0, (screenSize.height - cameraHeight) / 2.0)
imag.cameraViewTransform = CGAffineTransformScale(imag.cameraViewTransform, scale, scale)

我用这个方法来计算比例。

// get the screen size
CGSize screenSize = [[UIScreen mainScreen] bounds].size;
// establish the height to width ratio of the camera
float heightRatio = 4.0f / 3.0f;
// calculate the height of the camera based on the screen width
float cameraHeight = screenSize.width * heightRatio;
// calculate the ratio that the camera height needs to be scaled by
float scale = screenSize.height / cameraHeight;
imagePicker.cameraViewTransform = CGAffineTransformMakeScale(scale, scale);

这在iOS 10上对我很有用:

let screenSize = UIScreen.main.bounds.size
let cameraAspectRatio = CGFloat(4.0 / 3.0)
let cameraImageHeight = screenSize.width * cameraAspectRatio
let scale = screenSize.height / cameraImageHeight
imagePickerController.cameraViewTransform = CGAffineTransform(translationX: 0, y: (screenSize.height - cameraImageHeight)/2)
imagePickerController.cameraViewTransform = imagePickerController.cameraViewTransform.scaledBy(x: scale, y: scale)

我的问题解决了:)

//Camera is 426 * 320. Screen height is 568.  Multiply by 1.333 in 5 inch (iPhone5) to fill vertical

CGAffineTransform translate = CGAffineTransformMakeTranslation(0.0, 71.0); //This slots the preview exactly in the middle of the screen by moving it down 71 points
self.imagePickerController.cameraViewTransform = translate;

CGAffineTransform scale = CGAffineTransformScale(translate, 1.333333, 1.333333);
self.imagePickerController.cameraViewTransform = scale;

尝试使用此代码:

picker.wantsFullScreenLayout = YES;
CGAffineTransform translate = CGAffineTransformMakeTranslation(0.0, 71.0);
CGAffineTransform scale = CGAffineTransformScale(translate, 1.333333, 1.47);
picker.view.transform = scale;

PickerViewController.m    
#define CAMERA_TRANSFORM  1.8

- (void)viewDidAppear:(BOOL)animated
{
 if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
       // type = UIImagePickerControllerSourceTypeCamera;

        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.allowsEditing = NO;
        picker.delegate   = self;
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
        picker.showsCameraControls=NO;
        picker.extendedLayoutIncludesOpaqueBars = YES;
        picker.cameraViewTransform = CGAffineTransformScale(picker.cameraViewTransform, CAMERA_TRANSFORM , CAMERA_TRANSFORM);

        [self presentViewController:picker animated:YES completion:nil];
    }else{

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Message"
                                                        message:@"Device have no camera"
                                                       delegate:self
                                              cancelButtonTitle:@"OK"
                                              otherButtonTitles:nil];
        [alert show];
    }
}