Understanding the Photo Display by Section of the Collectionview

I am using collection view for view.
Allows you to add sections to the collection view later.
Then, I would like to tap the button attached to the added section so that I can select and view each photo from the camera roll.

For now, you can add a section and select a photo from the camera roll to display it, but when you select a photo, the selected photo for all sections is displayed.
I think it's probably because I updated all the data in the collection view in reloadData...

// Processing after image selection
- (void) imagePickerController: (UIImagePickerController*)picker didFinishPickingMediaWithInfo: (NSDictionary*) info
{
    NSLog (@ "After Image Selection");
    UIImage* originalImage=(UIImage*) [ info objectForKey: UIImagePickerControllerOriginalImage];
    UIImage*editImage=(UIImage*) [ info objectForKey: UIImagePickerControllerEditedImage];

    UIImage* saveImage;

    if(editImage){
        saveImage=editImage;
    } else{
        saveImage=originalImage;
    }

    // Display the selected image here
    [self addSelectedPicture:self item:saveImage]

    [picker dismissViewControllerAnimated:YES completion:nil];

    // If you do not reload here, it will not appear when you return after selecting the image.
    self.collectionView reloadData;
    // [self.collectionView reloadSections: NSIndexSetindexSetWithIndex:0];
}


- (void) addSelectedPicture: (SubjectViewController*) controller item: (UIImage*) item
{
    [_images addObject:item];

    self.collectionView reloadData;
    // [self.collectionView reloadSections: [NSIndexSetindexSetWithIndex:0]];
}




- (void) addItemViewControllerDidFinish2: (AddDateViewController*) controller item: (NSString*) item
{
    if(!_objects4){
        _objects4 = [[NSMutableArray alloc] init];
    }

    [_objects4 insertObject: item atIndex:0];

    [_sectionDates insertObject: controller.makeDate.date atIndex:0];

    // ReloadData here will update the entire section every time it is added
    [_collectionView reloadData];
    // If you do the following, you will get an error because there is no section at first.
    // [self.collectionView reloadSections: [NSIndexSetindexSetWithIndex:0]];

    [self-dismissViewControllerAnimated: YES completion: NULL] 
}




// The image to be displayed in the cell of the collection
- (UICollectionViewCell*) collectionView: (UICollectionView*) collectionView cellForItemAtIndexPath: (NSIndexPath*) indexPath
{
    UICollectionViewCell*cell;
    cell=[collectionView requestReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];

    UIImageView* imageView= (UIImageView*) [cell viewWithTag:1];

    imageView.image=_images [indexPath.row];

    return cell;
}

How do I add a section and display each individual image in that section?
I'd like someone to tell me.
Thank you for your cooperation.

ios objective-c iphone

2022-09-30 20:35

1 Answers

You seem to be holding the selected image in a one-dimensional array.
If you want to add a section instead of a cell, wouldn't it be better to keep it in a two-dimensional array?

One-dimensional array

// When the section changes, the row returns to zero, so the same position is obtained.
_images [indexPath.row];

2D array

//Keep images per section
_images [indexPath.section] [indexPath.row];

----------

[_images addObject:item];

Has this been corrected?
Place the array in the array, so

[_imagesaddObject:@[item]];
　or
_images[0]=@[item];

// This is what it looks like when you write it down.
NSMutableArray*array= [NSMutableArray new];
array addObject:item;
[_images addObject:array];

The description is similar to .
You need to change the subscripts from the example above, but
The implementation described in the question does not get indexPath in addSelectedPicture, so
I think you will need to consider that.

2022-09-30 20:35

If you have any answers or tips

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