Iphone – Uiimageview inside uiscrollview position is not centered

iphoneuiimageviewuiscrollviewzooming

I am developing an app for iPhone/iPad using Objective C. In my app I am having an UiScrollView which is having an UIImageView inside it. I can scroll and Zoom the Image inside the Scroll View.

All works fine.But my problem is that when I am loading the Image Inside a uiscrollview, its position is at something at center but not exactly.

I want that either my image should be center aligned or at the Top Left corner.

I had set the contentoffset to (0,0) and also tried setting the AutoresizingMask to different values.

Please let me know if somebody has any idea or solution.

Best Answer

contentoffset is something of the scrollview and is probably not right for this situation. If you want the image to be in the center do this:

imageview.center = scrollview.center;

If you want the image to be at the top left corner of the scrollview do this:

imageview.frame = CGRectMake(0,0,image_width,image_height);

Good luck!

Related Solutions

Ios – Center content of UIScrollView when smaller

I've got very simple solution! All you need is to update the center of your subview (imageview) while zooming in the ScrollViewDelegate. If zoomed image is smaller than scrollview then adjust subview.center else center is (0,0).

- (void)scrollViewDidZoom:(UIScrollView *)scrollView 
{
    UIView *subView = [scrollView.subviews objectAtIndex:0];

    CGFloat offsetX = MAX((scrollView.bounds.size.width - scrollView.contentSize.width) * 0.5, 0.0);
    CGFloat offsetY = MAX((scrollView.bounds.size.height - scrollView.contentSize.height) * 0.5, 0.0);

    subView.center = CGPointMake(scrollView.contentSize.width * 0.5 + offsetX, 
                                 scrollView.contentSize.height * 0.5 + offsetY);
}

Iphone – Center UIImageView inside UIScrollView without contentInset

This code should work on most versions of iOS (and has been tested to work on 3.1 upwards, which is all I currently have access to).

It's based on the Apple WWDC code mentioned in Jonah's answer.

Add the below to your subclass of UIScrollView, and replace tileContainerView with the view containing your image or tiles:

- (void)layoutSubviews {
    [super layoutSubviews];

    // center the image as it becomes smaller than the size of the screen
    CGSize boundsSize = self.bounds.size;
    CGRect frameToCenter = tileContainerView.frame;

    // center horizontally
    if (frameToCenter.size.width < boundsSize.width)
        frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width) / 2;
    else
        frameToCenter.origin.x = 0;

    // center vertically
    if (frameToCenter.size.height < boundsSize.height)
        frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height) / 2;
    else
        frameToCenter.origin.y = 0;

    tileContainerView.frame = frameToCenter;
}

Best Answer

Related Solutions

Ios – Center content of UIScrollView when smaller

Iphone – Center UIImageView inside UIScrollView without contentInset

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