设置集合视图单元格的动态宽度和高度

Question

Actually i want to set button dynamically and title of button appear Dynamic i have try this and got width of Dynamic content but am not setting cell width and height.

- (void)viewDidLoad {
    [super viewDidLoad];

    ContentArray = [[NSMutableArray alloc]init];

    self.collectionview.delegate = self;
    self.collectionview.dataSource =self;
    self.collectionview.backgroundColor = [UIColor clearColor];


    [ContentArray addObject:@"Planning"];
    [ContentArray addObject:@"Resources"];
    [ContentArray addObject:@"Human Resources"];
    [ContentArray addObject:@"Agriculture"];
    [ContentArray addObject:@"Resources management"];


}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
    {
        return ContentArray.count;
    }


    - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
    {

        CollectionViewCell * Cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"CollectionViewCell"forIndexPath:indexPath];

        [Cell.button setTitle:[ContentArray objectAtIndex:indexPath.row] forState:UIControlStateNormal];

        return Cell;
    }


- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
    {


        CGRect rect = [[ContentArray objectAtIndex:indexPath.row ] boundingRectWithSize:CGSizeMake(HUGE_VALF, 50) options:NSStringDrawingUsesFontLeading attributes:nil context:nil] ;


        return CGSizeMake(rect.size.width, 50);
    }

and output is like this

This is perfect i think if i make cell dynamic width and height, so please guide me through this.

Answer 1

pragma mark - GetHeightFromString

- (CGFloat)getTextHeightFromString:(NSString *)text ViewWidth:(CGFloat)width WithPading:(CGFloat)pading FontName:(NSString *)fontName AndFontSize:(CGFloat)fontSize
{
    NSDictionary *attributes = @{NSFontAttributeName: [UIFont fontWithName:fontName size:fontSize]};
    CGRect rect = [text boundingRectWithSize:CGSizeMake(width, MAXFLOAT)
                                     options:NSStringDrawingUsesLineFragmentOrigin
                                  attributes:attributes
                                     context:nil];
    //NSLog(@"rect.size.height: %f", rect.size.height);
    return rect.size.height + pading;
}

Get height of the string from this method and add this to origional height of your cell or label or button whatever you want to use.

For example:

  - (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
    {
        YourCellClass *myCell =  (YourCellClass*) [collectionView cellForItemAtIndexPath:indexPath];  

        CGFloat  sizeFromString   = [self getTextHeightFromString:itemObject.MenuDescription ViewWidth:myCell.frame.size.width WithPading:10 FontName:@"HelveticaNeue" AndFontSize:13];

        return CGSizeMake(sizeFromString, sizeFromString);
    }

You might need to change the height of inner label too, for this use same method in cellForItemAtIndexPath method of your UICollectionView . Further more you can customize your own way.

Answer 2

In Swift 2.0:
Using a UICollectionViewFlowLayout enable cell auto-sizing.
The following code inside a UICollectionViewController subclass will enable auto-sizing for it's flow layout.

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib. 
    if let cvl = collectionViewLayout as? UICollectionViewFlowLayout {
        cvl.estimatedItemSize = CGSize(width: 150, height: 75)
    }

}

Answer 3

You can put different sizes in landscape & portrait mode try this -

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout *)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{    
    // Adjust cell size for orientation
    if (UIDeviceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation])) {
        return CGSizeMake(rect.size.width, 50);
    }
    return CGSizeMake(rect.size.width, 50);
}

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
    [self.collectionView performBatchUpdates:nil completion:nil];
}

you can call invalidateLayout method on the .collectionViewLayout property of your UICollectionView

- (void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];
    [yourCollectionView.collectionViewLayout invalidateLayout];
}

Answer 4

You can try this...

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return CGSizeMake(width, height);
}

width, height are the dynamically calculated value

Thanks