Within my view I create a scrollview with a width of 320 and a height of 70.
Responding to the user touching a button, I expand the scrollview, so it is 380(h) x 320(w) in size.
The code for this is shown below:
CGRect scrollviewFrame = CGRectMake(0, 30, 320, 380);
[scrollView setFrame:scrollviewFrame];
[self layoutScrollImages:YES];
CGSize srect = CGSizeMake([scrollView bounds].size.width, (kNumImages * kScrollObjHeight));
[scrollView setContentSize:srect];
As I debug this project, I can see that srect is 320 (w) x 8000 (h) in size; however my issue is the scrollable area (where the user can actually touch to scroll the scrollview) remains the same as when it was it's original size.
I'm obviously missing something, does anyone know what it is?
Edit: I have created a sample project to illustrate the issue I am having, it is available here: http://dl.dropbox.com/u/9930498/ScrollViewTest.zip
I think , you have issue with your below line of code.
CGSize srect = CGSizeMake([scrollView bounds].size.width, (kNumImages * kScrollObjHeight));
[scrollView setContentSize:srect];
debug your program and see the content of srect , Also let us know the value of below two constant
kNumImages,kScrollObjHeight .
You need to change the contentSize of the scrollview as well as the frame.
Maybe this will help aswell: UIScrollView Class Reference
Do this when setting the new size
scrollView.scrollEnabled = YES;
scrollView.showsHorizontalScrollIndicator = YES;
scrollView.showsVerticalScrollIndicator = YES;
[scrollView setFrame:CGRectMake(0, 30, 320, 380)];
CGSize srect = CGSizeMake([scrollView bounds].size.width, (kNumImages * kScrollObjHeight));
[scrollView setContentSize:srect];
[self layoutScrollImages:YES];
Related
I'm new to ios programming.
I want users to be able to scroll screen, so I initialized UIScrollView and add other views into the instance of UIScrollView.
But, I'm not able to scroll screen and I don't see a scrollbar.
This is my code I wrote.
This view controller extends from UIViewController.
What is wrong with this?
Please help me.
Thank you very much!!
- (void)viewDidLoad
{
[super viewDidLoad];
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.view.frame];
scrollView.contentSize = self.view.frame.size;
[self.view addSubview:scrollView];
UIImage *img = [UIImage imageNamed:#"avatar.png"];
UIImageView *profileImg = [[UIImageView alloc] initWithImage:img];
CGPoint newPoint = self.view.center;
newPoint.y = 300;
profileImg.center = newPoint;
[scrollView addSubview:profileImg];
}
you need to set a content size and scroll enabled
[scrollView setFrame:self.view.bounds]; // not needed to be able to scroll
[scrollView setScrollEnabled:YES]; // needed to be able to scroll, defaults to YES
[scrollView setContentSize:CGSizeMake(320, 500)]; // the important part that is needed to be able to scroll
the 320 and 500 are desired maxed distances of scrolling to, this is not the actual scroll distance but the width and height of pixels that will be shown, you can think of the scroll view being a window and these values being the world outside
that is where you main error is, the width and height of your scroll view is the same width and height of the context size, therefore; it's like you are looking through a 1ft by 1ft window in to a room that is only 1ft by 1ft
UIScrollView Documentation
I am displaying multiple labels inside a UIScrollView, I can get them to display and I can get them to scroll, but a label at the top of the screen is cut off and is not visible unless you pull down. I have a tried adjusting the UIScrollViews content size, frame etc. all to no avail. Please help! Code:
[self.view addSubview: scrollView];
scrollView.scrollEnabled = YES;
int scrollWidth = 120;
int scrollHeight = 1000;
scrollView.contentSize = CGSizeMake(scrollWidth,scrollHeight);
scrollView.frame = CGRectMake(0, 0, 320, 400);
Set the contentOffset to (0,0).
I am new in iOS programming, and my scroll view is not scrolling horizontally.
I want to make it possible to scroll horizontally, vertically it works correctly, but horizontally it not working please help me. I used the following code.
scrollView.frame = CGRectMake(0, 0, 600, 460);
[scrollView setContentSize:CGSizeMake(320, 678)];
You can set the frame of scrollview is CGRectMake(0, 0, 320, 460) and content size is [scrollView setContentSize:CGSizeMake(600, 678)]; because scroll is enabled when the scroll content size is greater then the frame size of scroll view
Try the following . this is working code for me . I am adding the images on horizontal scroll view .
int scrollWidth=60;
for (int i=0;i<array.count;i++)
{
UIImageView *imageView1=[[UIImageView alloc]initWithFrame:CGRectMake(scrollWidth,8,50,40)];
imageView1.userInteractionEnabled=YES;
imageView1.backgroundColor=[array objectAtIndex:i];
[scrollView addSubview:imageView1];
scrollWidth=scrollWidth+80;
}
[scrollView setContentSize:CGSizeMake(scrollWidth, 30)];
You set the width 600 but the content size is 320 so in that case you can't scroll horizontally. So you need to set width of content.
[scrollView setContentSize:CGSizeMake(600, 678)];
//use
scrollView.frame = CGRectMake(0, 0, 320, 460);
scrollView.contentSize = CGSizeMake(600,678);
How do I set the starting point of a UIScrollView? I would like to add a UIImageView left of the UIScrollView but changing the contentSize only adds scrolling room to the right of the scrollview. How do I add an ImageView left of the scrollView's (0,0) point and make it part of the scrollview's content size?
Hopefully I've got what you're trying to do here. I think this just takes a few turns with the contentOffset to get right.
Starting off;
Add the scrollView at frame (0,0,320,480) - its a full screen scroller
set contentSize to (320*3, 480) - it now has a content with the width of 3 'pages'
Add your imageView as a subview to the scrollView at frame (320,0,320,480)
set contentOffset of the scrollView to (320, 0) - this will move the content of the scrollView left, in the negative x direction by 320
Now your imageView will be on screen, but it will have a 320px width both on the left and right on the scroller content.
(Note that in the code below, i've simply added a UIView and not an imageView)
UIScrollView *scroller = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
scroller.delegate = self;
scroller.pagingEnabled = YES;
scroller.backgroundColor = [UIColor blueColor];
scroller.contentSize = CGSizeMake(960, 480);
UIView *imgView = [[UIView alloc] initWithFrame:CGRectMake(320, 0, 320, 480)];
[imgView setBackgroundColor:[UIColor redColor]];
[scroller addSubview:imgView];
[scroller setContentOffset:CGPointMake(320, 0)];
[self.view addSubview:scroller];
Does that help?
Actually the best solution to start in the middle of the scroller if you are in a iPhone you should
[scroller setContentOffset:CGPointMake(320, 0)];
[self.view addSubview:scroller];
And for iPad
[scroller setContentOffset:CGPointMake(1024, 0)];
[self.view addSubview:scroller];
Try setting the Content offset.
[scrollView setContentOffset:CGPointMake(320, 0.0)];
If you're simply looking to set where the scroller content should be positioned at the start, you could do so with the - (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated method which will scroll the content to the point specified in the method.
Let me know if this is not what you wanted to know, and I'll get back to ya!
Cheers.
The key to setting the starting point, is to assign bounds with xy coordinates different than zero. Like this
lazy var contentView: UIView = {
let size = CGFloat(5000)
let view = UIView(frame: CGRectZero)
view.frame = CGRectMake(0, 0, size, size)
view.bounds = CGRectMake(-size/2, -size/2, size, size)
return view
}()
func centerContent() {
let frame = UIEdgeInsetsInsetRect(self.scrollView.bounds, self.scrollView.contentInset)
let navigationBarHeight = self.scrollView.contentInset.top
let x = (self.scrollView.contentSize.width/2) - (frame.size.width/2)
let y = (self.scrollView.contentSize.height/2) - (frame.size.height/2) - navigationBarHeight
self.scrollView.contentOffset = CGPointMake(x, y)
}
I'm using a UIView to control the layout of my view (along with a view controller). I want UIScrollView to only use half of the vertical screen. That works fine if I use the upper half of the screen, but not the bottom half.
Here's the relevant code from the UIViewController:
- (void)loadView {
CGRect fullFrame = [[UIScreen mainScreen] applicationFrame];
//trying to put the scroll view on the bottom half of the screen, but does not work.
CGRect halfFrame = CGRectMake(0, fullFrame.size.height / 2 ,
fullFrame.size.width, fullFrame.size.height / 2);
//use this instead for the scroll view to go to the top half of the screen (and work properly)
//CGRect halfFrame = CGRectMake(0, 0 , fullFrame.size.width, fullFrame.size.height / 2);
UIScrollView* sv = [[UIScrollView alloc] initWithFrame:halfFrame];
[sv setContentSize:CGSizeMake(3 * halfFrame.size.width, halfFrame.size.height)];
CGRect stencilFrame = halfFrame;
UIView *leftView = [[UIView alloc] initWithFrame:stencilFrame];
stencilFrame.origin.x += stencilFrame.size.width;
UIView *centerView = [[UIView alloc] initWithFrame:stencilFrame];
stencilFrame.origin.x += stencilFrame.size.width;
UIView *rightView = [[UIView alloc] initWithFrame:stencilFrame];
//mix up the colors
[leftView setBackgroundColor:[UIColor redColor]];
[centerView setBackgroundColor:[UIColor greenColor]];
[rightView setBackgroundColor:[UIColor blueColor]];
//add them to the scroll view
[sv addSubview:leftView];
[sv addSubview:centerView];
[sv addSubview:rightView];
//turn on paging
[sv setPagingEnabled:YES];
UIView *containerView = [[UIView alloc]initWithFrame:fullFrame];
[containerView addSubview:sv];
[self setView:containerView];
}
Thank you in advance for any advice or help.
I figured it out. The crux of the problem is that views within the scroll view are initialized with the same frame as the scroll view itself. When the scrollView is initialized with halfFrame, the origin is (0, half the full screen size), which is ok since that is relative to the application window itself. However, the views that are put inside the scrollView (like leftView) are initialized to halfFrame, but in this case the origin is relative to the scrollView, effectively placing them off the screen. Setting the origin to (0,0) fixes this:
CGRect stencilFrame = CGRectMake(0, 0, fullFrame.size.width , fullFrame.size.height / 2);
contentSize must contain the rectangle of the view inside the scroll view. That is, the total size of all scrollable controls within. The frame of the UIScrollView decides how much scrolling is needed to let the user browse everything.
You don't have the "full frame" available if you have a nav bar or a tab bar. In general, code that uses [UIScreen mainScreen] for layout information is probably wrong.
Additionally, the status bar can change size if (for example) a call is in progress or tethering is enabled.
Instead, use any sane value for full frame and enable autoresizing:
CGRect fullFrame = {{0,0}, {320,480}};
...
sv.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleTopMargin;
EDIT: You also probably need to subclass UIScrollView and implement -setFrame: so that it also sets the content size and -layoutSubviews to do the correct layout.