关于 iphone：从相机中拍照并在 UIImageView 中显示


Taking a picture from the camera and show it in a UIImageView

我有一个包含一些字段(名称、价格、类别)和一个分段控件的视图，加上这个按钮来拍照。
如果我在模拟器(没有相机)上尝试这个，它可以正常工作：我可以从相机胶卷中选择图像，编辑它并返回到视图，这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视图时，除了 UIImageView 之外，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将它们放回"viewWillApper"" 方法，但应用程序崩溃。
开始想也许下面的方法有问题

编辑

我在这里找到了解决方案。我为 UIImage 类定义了一个新方法。 (点击链接获取更多信息)。然后我在 UIImageView 的框架上工作以适应新的维度，横向或纵向。

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-(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！如果我以横向拍摄一张照片，然后尝试以纵向拍摄另一张，则应用程序会崩溃。我必须发布一些东西吗？

我也遇到了同样的问题，使用相机时没有经过编辑的图像，您必须使用原始图像：

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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
    ...

如果在使用专辑时被裁剪，你当然必须重新裁剪：

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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;
}

相机模式也存在croprect信息，您需要检查您希望它的行为方式。

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要裁剪图像，我认为这可能会对您有所帮助

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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();
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