如何在iOS的nsuserdefaults中保存相机捕获的图像

Question

I would like to save the camera capture images in nsuserdefaults. To add the camera capture images in collection view. (I added it in Cemeracaptureviewcontroler) my problem is: create one array and add the capture images collection view is working fine. but when I moving back to another view controller and come back again to Cemeracaptureviewcontroler then capture images are not display. In array values the images are display null . when the images save means that image array like this values.

<UIImage: 0x7ae93f50> size {640, 424} orientation 0 scale 1.000000">

<UIImage: 0x7ae93f52> size {640, 424} orientation 0 scale 1.000000">

So I think store the images in user defaults and display in collection. How can I solve this issues help me.

///here i get the capture image in picker

if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary])
{
       UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
       imagePicker.sourceType =  UIImagePickerControllerSourceTypePhotoLibrary;
       imagePicker.delegate = self;
       imagePicker.allowsEditing = YES;
       [self presentViewController:imagePicker animated:YES completion:nil];
}

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{

    [picker dismissViewControllerAnimated:YES completion:Nil];

    originalImage = [info objectForKey:UIImagePickerControllerEditedImage];
    recipeImageView.image = [originalImage fixOrientation];

    [self.phto_arr_ addObject:originalImage];        
    [_collectionView reloadData];
}

Answer 1

You can save the images into NSUserDefults as,

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
    if(!self.phto_arr_){
         self.phto_arr_ = [[NSMutableArray alloc] init];
    }
    [self.phto_arr_ addObject: chosenImage];
    NSData *encodedObject = [NSKeyedArchiver archivedDataWithRootObject:self.phto_arr_];
    [[NSUserDefaults standardUserDefaults] setObject: encodedObject forKey:@"images"];
    [[NSUserDefaults standardUserDefaults] synchronize];
    [picker dismissViewControllerAnimated:YES completion:NULL];
}

and retrieve as,

- (void)viewWillAppear:(BOOL)animated {

    NSUserDefaults *userDefaults = (NSUserDefaults *)[NSUserDefaults standardUserDefaults];
    NSData *encodedObject = [userDefaults objectForKey:@"images"];
    self.phto_arr_ = (NSMutableArray *)[NSKeyedUnarchiver unarchiveObjectWithData:encodedObject];
    [_collectionView reloadData];
    [super viewWillAppear:animated];
}

Hope this may help you

Answer 2

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

UIImage *browsed_Image = [UIImage imageWithData:UIImageJPEGRepresentation([info objectForKey:UIImagePickerControllerEditedImage], 0.2)];

[picker dismissViewControllerAnimated:YES completion:^{
    if (browsed_Image) {
            dispatch_queue_t queue = dispatch_get_main_queue();
            dispatch_async(queue, ^{
                [[NSUserDefaults standardUserDefaults] setObject:UIImagePNGRepresentation(browsed_Image) forKey:@"keyname"];
            });
    }
}];
}

Answer 3

do not save images in defaults use..

- (void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info
{

 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
    UIImage  *image= [info objectForKey:UIImagePickerControllerEditedImage];
    NSData *data = UIImagePNGRepresentation(image);
    NSTimeInterval timeStamp = [[NSDate date] timeIntervalSince1970];
    NSNumber *timeStampObj = [NSNumber numberWithDouble:timeStamp];
    NSString *fileName = nil;
    fileName = [NSString stringWithFormat:@"PICT_%@.png", [timeStampObj stringValue]];
    NSString *localFilePath = [dataPath stringByAppendingPathComponent:fileName];
    [data writeToFile:localFilePath atomically:YES];
    dispatch_async(dispatch_get_main_queue(), ^{
      //if any UI task
          });
    });
}

datPath is dataPath = [documentsDirectory stringByAppendingPathComponent:@"<your relevent subdirectoryname>"]; now save the file path "localFilePath" in array and use it you can maintain its persistance by keeping its retain count higher or simply save this array of file paths in NSUserDefaults

you can set image as

[UIImage imageWithContentsOfFile:<localFilePath>]