Taking a picture from the camera and show it in a

问题:

I have a view with some fields (name, price, category) and a segmented control, plus this button to take picture.
If I try this on the simulator (no camera) it works properly: I can select the image from the camera roll, edit it and go back to the view, which will show all the fields with their contents .
But on my iphone, when I select the image after the editing and go back to the view, all the fields are empty exept for the UIImageView.
I also tried to save the content of the fields in variables and put them back in the "viewWillApper" method, but the app crashes.
Start to thinking that maybe there is something wrong methods below

EDIT

I found the solution here. I defined a new method to the UIImage class. (follow the link for more information).
Then I worked on the frame of the UIImageView to adapt itself to the new dimension, in landscape or portrait.

-(IBAction)takePhoto:(id)sender {
    if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera]) {
        self.imgPicker.sourceType = UIImagePickerControllerSourceTypeCamera;
        self.imgPicker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto;
    } else { 
        imgPicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    }
    [self presentModalViewController:self.imgPicker animated:YES];
}

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    [picker dismissModalViewControllerAnimated:YES];

    NSDate *date = [NSDate date];
    NSString *photoName = [dateFormatter stringFromDate:date];    
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUs    erDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    imagePath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.png", photoName]];

    UIImage *picture = [info objectForKey:UIImagePickerControllerOriginalImage];

    // ---------RESIZE CODE--------- //
    if (picture.size.width == 1936) {
        picture = [picture scaleToSize:CGSizeMake(480.0f, 720.0f)];
    } else {
        picture = [picture scaleToSize:CGSizeMake(720.0f, 480.0f)];
    }
    // --------END RESIZE CODE-------- //

    photoPreview.image =  picture;

    // ---------FRAME CODE--------- //
    photoPreview.contentMode = UIViewContentModeScaleAspectFit;
    CGRect frame = photoPreview.frame;
    if (picture.size.width == 480) {
        frame.size.width = 111.3;
        frame.size.height =167;
    } else {
        frame.size.width = 167;
        frame.size.height =111.3;
    }
    photoPreview.frame = frame;
    // --------END FRAME CODE-------- //


    NSData *webData = UIImagePNGRepresentation(picture);
    CGImageRelease([picture CGImage]);
    [webData writeToFile:imagePath atomically:YES];
    imgPicker = nil;
}

Now I have a new issue! If I take a picture in landscape, and try to take another one in portrait, the app crashs. Do I have to release something?

回答1:

I had the same issue, there is no edited image when using the camera, you must use the original image :

originalimage = [editingInfo objectForKey:UIImagePickerControllerOriginalImage];

if ([editingInfo objectForKey:UIImagePickerControllerMediaMetadata]) {
    // test to chek that the camera was used
    // especially I fund out htat you then have to rotate the photo
    ...

If it was cropped when usign the album you have to re-crop it of course :

if ([editingInfo objectForKey:UIImagePickerControllerCropRect] != nil) {
    CGRect cropRect = [[editingInfo objectForKey:UIImagePickerControllerCropRect] CGRectValue];
    CGImageRef imageRef = CGImageCreateWithImageInRect([originalimage CGImage], cropRect);
    chosenimage = [UIImage imageWithCGImage:imageRef]; 
    CGImageRelease(imageRef);
} else {
    chosenimage = originalimage;
}

The croprect info is also present for the camera mode, you need to check how you want it to behave.

回答2:

To Crop image i think this may help you

UIImage *croppedImage = [self imageByCropping:photo.image toRect:tempview.frame];

CGSize size = CGSizeMake(croppedImage.size.height, croppedImage.size.width);
UIGraphicsBeginImageContext(size);

CGPoint pointImg1 = CGPointMake(0,0);
[croppedImage drawAtPoint:pointImg1 ];

[[UIImage imageNamed:appDelegete.strImage] drawInRect:CGRectMake(0,532, 150,80) ];

UIImage* result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
croppedImage = result;

UIImageView *mainImageView = [[UIImageView alloc] initWithImage:croppedImage];

CGRect clippedRect = CGRectMake(0, 0, croppedImage.size.width,  croppedImage.size.height);

CGFloat scaleFactor = 0.5;

UIGraphicsBeginImageContext(CGSizeMake(croppedImage.size.width * scaleFactor, croppedImage.size.height * scaleFactor));
CGContextRef currentContext = UIGraphicsGetCurrentContext();

CGContextClipToRect(currentContext, clippedRect);   

//this will automatically scale any CGImage down/up to the required thumbnail side (length) when the CGImage gets drawn into the context on the next line of code
CGContextScaleCTM(currentContext, scaleFactor, scaleFactor);

[mainImageView.layer renderInContext:currentContext];

appDelegete.appphoto = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();