关闭应用程序后，从相机拍摄的照片不会出现在图像视图中

Question

I have two, my view on the. 1. imageview - img 2. Uibutton -takepic The aim of the app is to display an image on the ImageView. When I click the button I have two options. Or take a photo album, or take a photo camera. When I take a picture from the album, the image is saved in my application and listed on the imageview and when I close the app that will run in the background and returning to the app, the image persists. The problem is the camera, I take a picture when the camera is listed on the imageview and saved in the device's photo album. But when I close the app that will run in the background, and returns to the app, the image does not resides on the imageview Why?

It's my complete code:

-(void)viewDidLoad {
    [super viewDidLoad];


    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];

    NSURL *selectedImageURL = [NSURL URLWithString:[userDefaults objectForKey:@"selectedImageURL"]];
    if (selectedImageURL)
    {
        [self getImageFromAssetsAtURL:selectedImageURL completion:^(UIImage *image, NSError *error)
         {
             if (!error && image)
             {
                 self.img.image = image;
             }
         }];
    }
    // Creating a Circular Profile Image.
    self.img.layer.cornerRadius = self.img.frame.size.width / 2.0;
    self.img.clipsToBounds = YES;

    // Adding Border to image.
    self.img.layer.borderWidth = 6.0;
    self.img.layer.borderColor = [UIColor blackColor].CGColor;
}

-(void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(IBAction)takePic:(id)sender {

    // ALERT SHEET.
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];

    //CAMERA
    UIAlertAction *openCamrea = [UIAlertAction actionWithTitle:@"צלם" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action)
    {
        // If device has no camera.
        if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
        {
            UIAlertController *alertNoCamera = [UIAlertController alertControllerWithTitle:@"Error" message:@"Device has no camera" preferredStyle:UIAlertControllerStyleAlert];
            UIAlertAction *ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action){}];
            [alertNoCamera addAction:ok];
            [self presentViewController:alertNoCamera animated:YES completion:nil];
        }
        else// if  have a camera.
        {
           UIImagePickerController *picker = [[UIImagePickerController alloc] init];
           picker.delegate = self;
           picker.allowsEditing = YES;
           picker.sourceType = UIImagePickerControllerSourceTypeCamera;


           [self presentViewController:picker animated:YES completion:NULL];
        }
    }];
    // GALLERY
    UIAlertAction *openGallery = [UIAlertAction actionWithTitle:@"גלריה" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action)
    {
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsEditing = YES;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

        [self presentViewController:picker animated:YES completion:NULL];
    }];

    [alert addAction:openCamrea];
    [alert addAction:openGallery];

    [self presentViewController:alert animated:YES completion:nil];
}


-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    UIImage *image = info[UIImagePickerControllerOriginalImage];
    NSURL *selectedImageURL = info[UIImagePickerControllerReferenceURL];

    if(picker.sourceType == UIImagePickerControllerSourceTypeCamera)
    {
        UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
        // set image
        self.img.image = image;
    }
    else{
        self.img.image = image;
    }
    // save image url
    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
    [userDefaults setObject:selectedImageURL.absoluteString forKey:@"selectedImageURL"];
    [userDefaults synchronize];

    // set image
    self.img.image = image;

    // dismiss
    [self dismissViewControllerAnimated:YES completion:nil];

}
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
    [picker dismissViewControllerAnimated:YES completion:NULL];
}
// chkeing if image save on album ot not.
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
    UIAlertAction *ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action){}];
    if (error) // Unable to save the image
    {
        UIAlertController *alertErorr = [UIAlertController alertControllerWithTitle:@"Erorr" message:@"Unable to save image to Photo Album." preferredStyle:UIAlertControllerStyleAlert];
        [alertErorr addAction:ok];
        [self presentViewController:alertErorr animated:YES completion:nil];
    }
    else // All is well
    {
        UIAlertController *alertSuccess = [UIAlertController alertControllerWithTitle:@"Success" message:@"Image saved to Photo Album." preferredStyle:UIAlertControllerStyleAlert];
        [alertSuccess addAction:ok];

        self.img.image=image;
        [self presentViewController:alertSuccess animated:YES completion:nil];
    }
    [self dismissViewControllerAnimated:YES completion:NULL];
}
-(void)getImageFromAssetsAtURL:(NSURL *)imageURL completion:(void (^) (UIImage *, NSError *))completion
{
    PHFetchResult *result = [PHAsset fetchAssetsWithALAssetURLs:@[imageURL] options:nil];
    if (result.count == 1) {
        PHAsset *asset = result.firstObject;
        [[PHImageManager defaultManager] requestImageDataForAsset:asset options:nil resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {
            UIImage *selectedImage = [UIImage imageWithData:imageData];
            completion(selectedImage, nil);}];
    } else {
        completion(nil, nil);
    }
}

@end

Answer 1

Best way will be saving the image to your app sandbox ( Document Directory ). Normally I do not suggest saving image in NSUserDefaults , as NSUserDefaults should be used to store small settings but not raw image data.

When you have the image ready, save it in the app document folder. You can later remove the image from the saved path!!!

You can store the image path in the NSUserDefaults but not image!!!

To save the image:

Put this code in didFinishPickingMediaWithInfo method:

If the image is in UIImageJPEGRepresentation use .jpeg extension, if it is in UIImagePNGRepresentation use .png extension

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory, @"myImage.png"];
NSLog(@"filePath %@", filePath);
    NSError *error;
[image writeToFile:filePath atomically:NO];

To get back the image:

    NSArray *arrayPaths =
    NSSearchPathForDirectoriesInDomains(
                                        NSDocumentDirectory,
                                        NSUserDomainMask,
                                        YES);
    NSString *path = [arrayPaths objectAtIndex:0];
    NSString* fileName = [path stringByAppendingPathComponent:@"myImage.png"];

  UIImage *image=[UIImage imageWithContentsOfFile:fileName];

Answer 2

library pictures are saved pictures but when you take picture from camera for your app then this will not be saved any where... so it will be deleted when app goes in back ground .... first save image anywhere.... fast method is save it to NSUserDefaults like this:

[NSUserdefaults standardUserDefaults] setObject:YourImage forkey:"myImage"];

after this when u came to foreground then in you viewWillAppear method u can set your image like this

yourImageView.image = [NSUserDefaults standardUserDefaults] ObjectForKey:"myImage"];

Thats all..Good luck

Answer 3

Try this..

Take a "Strong" Property for "UIImage" say "myImage" and then assign it the image captured from the camera.

Now use the "myImage" when assigning image to imageView.