CODEWITHSUNDEEP
iosuitableviewuiviewuiscrollviewautolayout
hgwhittle
hgwhittle

Reputation: 9426

Paging UIScrollView on custom UITableViewCell with Autolayout

I'm trying to use a horizontal-paging UIScrollView in my custom UITableViewCell using Autolayout. I've successfully added the UIScrollView to the cell with all the proper constraints.enter image description here

My problem arises when I try to load the UIScrollView with views. I'm overriding the custom cell's layoutSubviews method and loading the ScrollView's views there because it's the only method I could find where Autolayout's constraints had been loaded. Thus, giving me accurate references to the ScrollView's size.

-(void)layoutSubviews {

    [super layoutSubviews];

    for(int i=0; i<self.scrollArray.count; i++) {
        CGRect frame;
        CGFloat width = self.theScrollView.frame.size.width;
        frame.origin.x = width * i;
        frame.origin.y = 0;
        frame.size = self.theScrollView.frame.size;

        UIView *subview = [[UIView alloc] initWithFrame:frame];
        [subview addSubview:[self.scrollArray objectAtIndex:i]];
        [self.theScrollView addSubview:subview];
    }

    CGSize contentSize = CGSizeMake(self.theScrollView.frame.size.width * self.scrollArray.count, self.theScrollView.frame.size.height);
    self.theScrollView.contentSize = contentSize;
    self.theScrollView.contentOffset = CGPointMake(0, 0);
}

However, layoutSubviews is called multiple times on my cell and thus adding more subviews than necessary to my UIScrollView. Is there a better method to load my subviews in that I'm not aware of? Or is there a way to use layoutSubviews but make sure my subviews are only loaded once into the UIScrollView?

Upvotes: 0

Views: 255

Answers (1)

HMHero
HMHero

Reputation: 2343

Move the part where you add the subviews to the scrollview to where you set the scrollArray and added the subviews to subview array property. In layoutsubviews, you should deal with setting frame only.

- (void)layoutSubviews
{
    [super layoutSubviews];

    //    self.theScrollView.frame = Make sure you set the scroll view frame;
    for(int i=0; i<self.scrollArray.count; i++) 
    {
        UIView *aView = [self.scrollArray objectAtIndex:i];
        aView.frame = CGRectMake(self.theScrollView.frame.size.width * i, 0, self.theScrollView.frame.size.width, self.theScrollView.frame.size.height);
    }

    self.theScrollView.contentSize = CGSizeMake(self.theScrollView.frame.size.width * self.scrollArray.count, self.theScrollView.frame.size.height);
    self.theScrollView.contentOffset = CGPointMake(0, 0);

}

- (void)partWhereYouSetScrollArray
{
    for(int i=0; i<self.scrollArray.count; i++)
    {
        [self.theScrollView addSubview:[self.scrollArray objectAtIndex:i]];
    }
}

- (void)prepareForReuse
{
   [super prepareForReuse];
   [[self.theScrollView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];
   [self.scrollArray removeAllObjects];
}

Upvotes: 1

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