从相机拍摄照片并将其显示在 UIImageView 中

Question

我有一个包含一些字段（名称、价格、类别）和分段控件的视图，以及用于拍照的按钮。
如果我在模拟器（无相机）上尝试此操作，它可以正常工作：我可以从相机胶卷中选择图像，对其进行编辑并返回到视图，该视图将显示所有字段及其内容。
但是在我的iPhone上，当我在编辑后选择图像并返回到视图时，除了 UIImageView 之外的所有字段都是空的。
我还尝试将字段的内容保存在变量中并放入他们回到“viewWillApper”方法中，但应用程序崩溃了。
开始思考下面的方法可能有问题

编辑

我找到了解决方案此处。我为 UIImage 类定义了一个新方法。 （点击链接了解更多信息）。
然后我研究了 UIImageView 的框架，使其适应新的尺寸（横向或纵向）。

-(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;
}

现在我有一个新问题！如果我拍摄一张横向照片，然后尝试拍摄另一张纵向照片，应用程序就会崩溃。我必须释放一些东西吗？

Answer 1

我遇到了同样的问题，使用相机时没有编辑过的图像，您必须使用原始图像：

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
    ...

如果在使用相册时裁剪了它，您当然必须重新裁剪它：

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;
}

相机的croprect信息也存在模式，您需要检查您希望它如何表现。

Answer 2

裁剪图像我想这可能对你有帮助

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();