I'm working with my UI completely programmatically here. When I add a UISegmentedControl to my UITableViewController's header view, it just fixes itself up there with no vertical space between the UINavigationBar. How can I add some padding between the UISegmentedControl and the UINavigationBar ?
Instantiate a UIView object and add your UISegmentedControl as a subview. Then set the UIView as your table's headerView. You'll be able to add padding by adjusting the frame of the UIView you created.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIView *headerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 150 /* <-- adjust this value for more or less padding */)];
UISegmentedControl *segControl = [[UISegmentedControl alloc] initWithItems:#[#"One", #"Two", #"Three"]];
segControl.frame = CGRectMake(0, 90, 200, 29);
//calculate the middle of the header view
CGFloat middleOfView = headerView.bounds.size.width / 2;
CGFloat middleOfSegControl = segControl.bounds.size.width / 2;
CGFloat middle = middleOfView - middleOfSegControl;
//position the seg control in the middle
CGRect frame = segControl.frame;
frame.origin.x = middle;
segControl.frame = frame;
[headerView addSubview:segControl];
self.theTableView.tableHeaderView = headerView;
}
Of course you can mess with the frames some more to get things positioned like you want them.
Related
Currently I'm trying to make 3 buttons in a horizontal group of 3 that have equal spacing
UIStackView * menuButtons = [[UIStackView alloc] initWithFrame:CGRectMake(0, 0, 60, 16)];
menuButtons.axis = UILayoutConstraintAxisHorizontal;
menuButtons.alignment = UIStackViewAlignmentBottom;
menuButtons.spacing = 6;
menuButtons.distribution = UIStackViewDistributionEqualSpacing;
UIButton* btnOne = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 16, 16)];
UIButton* btnTwo = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 16, 16)];
UIButton* btnThree = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 16, 16)];
[menuButtons addArrangedSubview:btnOne];
[menuButtons addArrangedSubview:btnTwo];
[menuButtons addArrangedSubview:btnThree];
ive noticed when I inspect the frame of the button views after adding them to my stackview programatically, they all show different sizes than originally set, when I expect them all to still be 16
ie: btnOne CGSize(17, 16), btnTwo CGSize(23.5, 23,5), btnThree CGSize(21.3, 21.3)
I don't understand why this happens, and I've tried all the distributions but I can't figure this out when I'm not setting the frames on these views anywhere else
Here is an example - based on your code - using auto-layout constraints.
Note that you do NOT need to specify width and height constraints for your UIStackView, as it will expand as needed to fit the arranged subviews.
If you do set a width constraint, you'll end up with (likely) unexpected results, because you've also specified fixed-width spacing of 6.
So, you would want either:
width constraint + UIStackViewDistributionEqualSpacing, or
no width constraint + default distribution + .spacing = 6
Hope this helps...
//
// StackTestViewController.m
//
// Created by Don Mag on 6/24/17.
//
#import "StackTestViewController.h"
#interface StackTestViewController ()
#end
#implementation StackTestViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self setupMenuButtons];
}
- (void)setupMenuButtons {
// instantiate a UIStackView
UIStackView *menuButtons = [[UIStackView alloc] init];
// horizontal
menuButtons.axis = UILayoutConstraintAxisHorizontal;
// spacing between arranged views
menuButtons.spacing = 6;
// instantiate 3 buttons
UIButton* btnOne = [UIButton new];
UIButton* btnTwo = [UIButton new];
UIButton* btnThree = [UIButton new];
// give 'em background colors so we can see them
btnOne.backgroundColor = [UIColor redColor];
btnTwo.backgroundColor = [UIColor greenColor];
btnThree.backgroundColor = [UIColor blueColor];
// for each button,
// tell it not to use Autoresizing Mask
// set width and height constraints each to 16
for (UIButton *b in #[btnOne, btnTwo, btnThree]) {
[b setTranslatesAutoresizingMaskIntoConstraints:NO];
[b.widthAnchor constraintEqualToConstant:16.0].active = YES;
[b.heightAnchor constraintEqualToConstant:16.0].active = YES;
}
// add them to the Stack View
[menuButtons addArrangedSubview:btnOne];
[menuButtons addArrangedSubview:btnTwo];
[menuButtons addArrangedSubview:btnThree];
// add the Stack View to self view
[self.view addSubview:menuButtons];
// tell Stack View not to use Autoresizing Mask
[menuButtons setTranslatesAutoresizingMaskIntoConstraints:NO];
// set X and Y position for the Stack View (just using 80,80 for this example)
[menuButtons.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor constant:80.0].active = YES;
[menuButtons.topAnchor constraintEqualToAnchor:self.view.topAnchor constant:80.0].active = YES;
}
#end
I have a collectionview that loads a series of cells. Some of the cells will have static images (which works well), but some might have multiple images that will need to be swipeable.
The UICollectionViewCell is the base view, the UIScrollView is within it (pinned to the top, left, bottom, and right of its superview).
Adding a UIImageView to the scrollview, I want to pin it to the top and left of the scrollview, but have its width and height be the same as the collection view cell, not the content size of the scrollview.
Then I'd like two additional images to be pinned to the top of the collection view cell, and the left closest view (in this case, the prior UIImageView).
The Storyboard would look something like this:
(with the other images off-screen and not displayed).
I decided to add the images via code:
There's a parent view, and a scrollview (attached to an IBOutlet).
The CollectionViewCell subclass contains:
#synthesize lbl, sv, pageControl;
- (void) awakeFromNib {
sv.userInteractionEnabled = NO;
sv.delegate = self;
pageControl.userInteractionEnabled = NO;
[self.contentView addGestureRecognizer:sv.panGestureRecognizer];
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat pageWidth = sv.frame.size.width;
float fractionalPage = sv.contentOffset.x / pageWidth;
NSInteger page = lround(fractionalPage);
self.pageControl.currentPage = page;
}
Then, within the View Controller's collectionView:cellForItemAtIndexPath method, I manually add images like so:
UIImageView *img = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[myArray objectAtIndex:indexPath.row]]];
img.frame = (CGRect) { 0, 0, cell.frame.size.width, cell.frame.size.height};
[cell.sv addSubview:img];
img = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[myArray objectAtIndex:indexPath.row + 1]]];
img.frame = (CGRect) { cell.frame.size.width, 0, cell.frame.size.width, cell.frame.size.height };
[cell.sv addSubview:img];
img = [[UIImageView alloc] initWithImage:[UIImage imageNamed:[myArray objectAtIndex:indexPath.row + 2]]];
img.frame = (CGRect) { cell.frame.size.width * 2, 0, cell.frame.size.width, cell.frame.size.height };
[cell.sv addSubview:img];
[cell.sv setContentSize:CGSizeMake(cell.frame.size.width * 3.0, cell.frame.size.height)];
I would have preferred a StoryBoard/Interface Builder way of doing this, but for now, this will suffice.
Context
This is a UIViewController which is within a UINavigationController stack
Within this UIViewController I'm adding a UILabel programmatically at (x,y) coordinates of (0,0)
I've experimented adding UILabel to self.view (this is within a UIViewController) or adding UILabel to a UIView, this UIView is self.containerView
self.containerView is created and added to the view through this code:
- (void)addContainerView
{
// Create a UIView with same frame as the screen bounds
CGRect containerViewFrame = [[UIScreen mainScreen] applicationFrame];
self.containerView = [[UIView alloc] initWithFrame:containerViewFrame];
// Give the UIView a red background
self.containerView.backgroundColor = [UIColor redColor];
// Add the view
[self.view addSubview:self.containerView];
}
The UILabel is added through this code:
- (void)addTestLabel
{
self.navigationController.navigationBarHidden = YES;
CGRect frame = CGRectMake(0, 0, 100, 100);
UILabel *label = [[UILabel alloc] initWithFrame:frame];
label.text = #"this is a test";
[self.view addSubview:label]; // OR [self.containerView addSubview:label]
}
When UILabel is added to self.view
When UILabel is added to self.containerView
Questions
Why doesn't the UILabel sit right at the top of the screen, even behind the status bar?
Why is there a difference between the yPos, dependent on whether it is added to self.view or self.containerView
Change the background color of the label and I think you'll see what's going on. The height of the label is 100 pixels and it's vertically centering it within that space. Change the height to 20 or 30 and try it again.
Currently, I have this feature in my app where I implemented a UIScrollview that is pretty thin in height but long in width...
As you can see, the UIScrollView is OVERLAPPING the backgroundview... Not that white background is a UIView to which I added the UIScrollView as a SUBVIEW.
Question is, how is the UIScrollView overlapping the black background content when it's just added to the subview?
Here is my init method for the UIScrollView..
self = [super init];
if (self) {
self.frame = CGRectMake(0, 0, 280, 70);
self.contentSize = CGSizeMake(480, 70);
self.showsHorizontalScrollIndicator = NO;
self.bounces = NO;
}
And here is how I added the UIScrollView to the UIView (whitebackground view) whose name is ForecastView:
_hourlyForecast = [[hourlyForecastScrollView alloc] init:_city state:_state icons:_icons times:_times temps:_temps];
_hourlyForecast.backgroundColor = [UIColor blueColor];
_hourlyForecast.frame = CGRectMake(20, 20, self.ForecastView.bounds.size.width, 70);
[_ForecastView addSubview:_hourlyForecast];
By default, a view will not clip it's subviews. To enable clipping, set the UIView clipsToBounds property, or set it in Interface Builder
(credit to Mugunth for the image)
I have a UIViewController, and I want to add a UIScrollView to it (enable scroll support), is it possible?
I know it is possible, if you have a UIScrollView to add a UIViewController to it, but I'm interested also if reverse was true, if I cann add a UIScrollView to an existing UIViewController, such that I get scrolling feature.
Edit
I think I have found an answer: Adding a UIViewController to UIScrollView
An UIViewController has a view property. So, you can add a UIScrollView to its view. In other words, you can add the scroll view to the view hierarchy.
This is can achieved by code or through XIB. In addition, you can register the view controller as the delegate for your scroll view. In this way, you can implement methods for performing different functionalities. See UIScrollViewDelegate protocol.
// create the scroll view, for example in viewDidLoad method
// and add it as a subview for the controller view
[self.view addSubview:yourScrollView];
You could also override loadView method for UIViewController class and set the scroll view as the main view for the controller you are considering.
Edit
I created a little sample for you. Here, you have a scroll view as a child of the view of a UIViewController. The scroll view has two views as children: view1 (blue color) and view2 (green color).
Here, I suppose you can scroll in only one direction: horizontally or vertically. In the following, if you scroll horizontally, you can see that the scroll view works as expected.
- (void)viewDidLoad
{
[super viewDidLoad];
UIScrollView* scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
scrollView.backgroundColor = [UIColor redColor];
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;
scrollView.showsVerticalScrollIndicator = YES;
scrollView.showsHorizontalScrollIndicator = YES;
scrollView.contentSize = CGSizeMake(self.view.bounds.size.width * 2, self.view.bounds.size.height);
[self.view addSubview:scrollView];
float width = 50;
float height = 50;
float xPos = 10;
float yPos = 10;
UIView* view1 = [[UIView alloc] initWithFrame:CGRectMake(xPos, yPos, width, height)];
view1.backgroundColor = [UIColor blueColor];
[scrollView addSubview:view1];
UIView* view2 = [[UIView alloc] initWithFrame:CGRectMake(self.view.bounds.size.width + xPos, yPos, width, height)];
view2.backgroundColor = [UIColor greenColor];
[scrollView addSubview:view2];
}
If you need to scroll only vertically you can change as follows:
scrollView.contentSize = CGSizeMake(self.view.bounds.size.width, self.view.bounds.size.height * 2);
Obviously, you need to rearrange the position of view1 and view2.
P.S. Here I'm using ARC. If you don't use ARC, you need to explicitly release alloc-init objects.