CODEWITHSUNDEEP
uiimageviewuicollectionviewuicollectionviewcell
dottorfeelgood
dottorfeelgood

Reputation: 41

change cell imageView in uicollectionview didSelectItemAtIndexPath method

I built a CollectionView controller with fixed imageView in 4 cells. I'd like the imageView to change on cell selection. Could you help me with this one?

Thank you

here's my code

CollectionView controller .m

....

-(NSInteger)numberOfSectionsInCollectionView:
(UICollectionView *)collectionView
{
    return 1;
}

-(NSInteger)collectionView:(UICollectionView *)collectionView
    numberOfItemsInSection:(NSInteger)section
{
    return 4;
}

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
                 cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    Cell *myCell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell"     forIndexPath:indexPath];

    UIImage *image;

    int row = [indexPath row];

    image = [UIImage imageNamed:@"ICUbedGREEN.png"];

    myCell.imageView.image = image;

    return myCell;
}

I'd like the image to change on press but I cannot figure it out...

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:    (NSIndexPath *)indexPath
{
    UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"ICUbedRED.png"]];

    cell.imageView.image = .....

     NSLog(@"elementselected");

}

Upvotes: 1

Views: 3689

Answers (2)

Taseen
Taseen

Reputation: 1255

It can be most stupid answer to your questions but it worked for me. I dont know how to work with KEy value paths as stated by Samuel.

Basically i made a NSMutableArray to store the status of icons, red or green..YES or NO.. 

selState = [[NSMutableArray alloc] initWithObjects:@"NO",@"NO",@"NO",@"NO",nil ];

and then in "ItemForIndexPath" method, checked the value to set image for that item

if ([[selState objectAtIndex:indexPath.row] isEqualToString:@"NO"]) {
    image = [UIImage imageNamed:@"ICUbedGREEN.png"];
}
else
{
    image = [UIImage imageNamed:@"ICUbedRED.jpg"];
}

When item is selected, using IndexPath, altered the value of NO into YES or vice versa..

if ([[selState objectAtIndex:indexPath.row] isEqualToString:@"NO"]) {
    [selState replaceObjectAtIndex:indexPath.row withObject:@"YES"];
}
else if ([[selState objectAtIndex:indexPath.row] isEqualToString:@"YES"]) {
    [selState replaceObjectAtIndex:indexPath.row withObject:@"NO"];
}

And then updated the collection View

[self.collectionView reloadData];

ALL CODE HERE 

@interface ViewController (){
NSMutableArray *selState;
}
@end
@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
// Do any additional setup after loading the view.

    selState = [[NSMutableArray alloc] initWithObjects:@"NO",@"NO",@"NO",@"NO",nil ];
}

-(NSInteger)numberOfSectionsInCollectionView:
(UICollectionView *)collectionView
{
    return 1;
}

-(NSInteger)collectionView:(UICollectionView *)collectionView
numberOfItemsInSection:(NSInteger)section
{
    return 4;
}

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
             cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    Cell *myCell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];

    UIImage *image;


    if ([[selState objectAtIndex:indexPath.row] isEqualToString:@"NO"]) {
        image = [UIImage imageNamed:@"ICUbedGREEN.png"];
    }
    else
    {
        image = [UIImage imageNamed:@"ICUbedRED.jpg"];
    }


    myCell.imageView.image = image;

    return myCell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:        (NSIndexPath *)indexPath
{
    if ([[selState objectAtIndex:indexPath.row] isEqualToString:@"NO"]) {
        [selState replaceObjectAtIndex:indexPath.row withObject:@"YES"];
    }
    else if ([[selState objectAtIndex:indexPath.row] isEqualToString:@"YES"]) {
        [selState replaceObjectAtIndex:indexPath.row withObject:@"NO"];
    }

    [self.collectionView reloadData];
}

@end

Thanks

EDITING---->>

the above code in ItemForIndexPath can also be written in 

image = [[selState objectAtIndex:indexPath.row] isEqualToString:@"NO"] ?
             [UIImage imageNamed:@"ICUbedGREEN.png"] : [UIImage imageNamed:@"ICUbedRED.jpg"];

END EDITING

Upvotes: 1

Samuel
Samuel

Reputation: 401

in your subclass for UICollectionViewCell implement the KVO listening method. Make sure you set multiselection to true if you want it to be deselected.

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{
 if ([keyPath isEqualToString@"selected"])
 {
      // check value of self.selected to know what you are currently.
      // change picture of image here
 }

}

in your cells init method you will need to add yourself as a listener so

 [self addObserver:self forKeyPath:@"selected" options:nil context:nil];

Upvotes: 1

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