I have some weird margins in a UILabel when setting the preferredMaxLayoutWidth property of a UILabel inside a UITableViewCell. Do you know some behaviour like that?
I added the preferredMaxLayoutWidth like that:
- (void)layoutSubviews {
self.titleLabel.preferredMaxLayoutWidth = self.titleLabel.frame.size.width;
[self.titleLabel sizeToFit];
self.shortDescriptionLabel.preferredMaxLayoutWidth = self.shortDescriptionLabel.frame.size.width;
[self.titleLabel sizeToFit];
[super layoutSubviews];
}
The Result is something like that:
As you see the title label has 14px margins and I don't know where they are from.
I already tried to call sizeToFit, but that doesn't helped.
The problem here is that the label's width is set to the width of the storyboard or xib which it is instantiated from (check the width inside of layoutSubviews and you'll see that it is very wrong). You will have to set preferredMaxLayoutWidth outside of this. What I have ended up doing is setting preferredMaxLayoutWidth to the width of the tableView minus any padding for the labels (I used a constraint group for this), which should be the same as the cell width.
So you'll need the following in method you do your cell configuration in (called from both tableView:cellForRowAtIndexPath: and tableView:heightForRowAtIndexPath:
Related
In my UIViewController, I have a non-editable attributed UITextView with scrolling enabled, and I would like to resize the height of the scrolling text to accommodate all screen size widths without having extra white space. I am using AutoLayout and set up outlets for the textview and its height constraint. In the view controller's viewDidLoad method I use the sizeThatFits method to update the textview height, but the resulting size is too small.
- (void)viewDidLoad{
[super viewDidLoad];
NSLog(#"INIT HEIGHT: %f, myTextView.frame.size.height);
CGSize sizeToFit =
[myTextView sizeThatFits: CGSizeMake(myTextView.frame.size.width, MAXFLOAT)];
myTextViewHeightConstraint.constant = sizeToFit.height;
[myTextView updateConstraints];
[myTextView layoutIfNeeded];
NSLog(#"NEW HEIGHT: %f", myTextView.frame.size.height);
}
The log indicates the height was indeed changed from my default of 4000 to 2502, but with 2502 I only see about half of my text via scrolling. I am avoiding nesting the text view in a scroll view, as one solution suggests, since this is discouraged in documentation. What am I missing? Thanks in advance.
I found that the frame of a UITextView will automatically size to its content, so dynamically setting it is not necessary. sizeThatFits is a UIView method and doesn't modify the size of the text content, but rather the size of the window that the text appears in. The only code I needed was to scroll the text to the top:
[myTextView scrollRectToVisible: CGRectMake(0,0,1,1) animated:NO];
This, as well as any Autolayout constraint updates shouldn't be made in viewDidLoad, but rather in viewDidLayoutSubviews or viewWillAppear. Best placement could probably be explained better - I'm open to comments.
I am writing an app and I want to make a textfield background turn white.
So far this is my code:
- (void)viewDidLoad
{
UITextField *txtfield = UsernameTextField;
[txtfield setBackgroundColor:[UIColor colorWithWhite:1 alpha:0.5] ];
txtfield.layer.borderColor = [UIColor blackColor].CGColor;
txtfield.layer.borderWidth = 1;
txtfield.borderStyle = UITextBorderStyleRoundedRect;
[super viewDidLoad];
// Do any additional setup after loading the view.
}
But this code have a result like this:
and i tried this code , to increast alpha
[txtfield setBackgroundColor:[UIColor colorWithWhite:1 alpha:0.8] ];
still the same
and also i see this post
iPhone UITextField background color
and i tried
but it still the same
Why textfield wont turn to white?
First thing first you should
[super viewDidLoad] should be the first statement in - (void)viewDidLoad after initialising parent child should do initialise.
Second
Please check the order of views put on view controller bring UsernameTextField to top of all views or you can call [self.view bringSubviewToFront:txtfield] in code
Third
Only by setting alpha to 1.0 you can see complete white background.
and finally is you still don't get it resolved then there is some changes you did in xib/storyboard view. So to reset just delete textfield and add it again.
In order to change background color it's important to set the border to None
txtfield.borderStyle = UITextBorderStyleNone;
Details: Changing background colour within a TextField in Interface Builder
iPhone UITextField background color
From Apple Doc:
When set, the image referred to by this property replaces the standard appearance controlled by the borderStyle property. Background images are drawn in the border rectangle portion of the text field. Images you use for the text field’s background should be able to stretch to fit.
My UICollectionView cells contain UILabels with multiline text. I don't know the height of the cells until the text has been set on the label.
-(CGSize)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout*)collectionViewLayout
sizeForItemAtIndexPath:(NSIndexPath *)indexPath;
This was the initial method I looked at to size the cells. However, this is called BEFORE the cells are created out of the storyboard.
Is there a way to layout the collection and size the cells AFTER they have been rendered, and I know the actual size of the cell?
I think your are looking for the invalidateLayout method you can call on the .collectionViewLayout property of your UICollectionView. This method regenerates your layout, which in your case means also calling -collectionView: layout: sizeForItemAtIndexPath:, which is the right place to reflect your desired item size. Jirune points the right direction on how to calculate them.
An example for the usage of invalidateLayout can be found here. Also consult the UICollectionViewLayout documentation on that method:
Invalidates the current layout and triggers a layout update.
Discussion:
You can call this method at any time to update the layout information. This method invalidates the layout of the collection view itself and returns right away. Thus, you can call this method multiple times from the same block of code without triggering multiple layout updates. The actual layout update occurs during the next view layout update cycle.
Edit:
For storyboard collection view which contains auto layout constraints, you need to override viewDidLayoutSubviews method of UIViewController and call invalidateLayout collection view layout in this method.
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
[yourCollectionView.collectionViewLayout invalidateLayout];
}
subclass UICollectionViewCell and override layoutSubviews like this
hereby you will anchor cell leading and trailing edge to collectionView
override func layoutSubviews() {
super.layoutSubviews()
self.frame = CGRectMake(0, self.frame.origin.y, self.superview!.frame.size.width, self.frame.size.height)
}
Hey in the above delegate method itself, you can calculate the UILabel size using the below tricky way and return the UICollectionViewCell size based on that calculation.
// Calculate the expected size based on the font and
// linebreak mode of your label
CGSize maximumLabelSize = CGSizeMake(9999,9999);
CGSize expectedLabelSize =
[[self.dataSource objectAtIndex:indexPath.item]
sizeWithFont:[UIFont fontWithName:#"Arial" size:18.0f]
constrainedToSize:maximumLabelSize
lineBreakMode:NSLineBreakByWordWrapping];
- (void)viewDidLoad {
self.collectionView.prefetchingEnabled = NO;
}
In iOS 10, prefetchingEnabled is YES by default. When YES, the collection view requests cells in advance of when they will be displayed. It leads to crash in iOS 10
I want to change the titleView of navigationBar with a regular text field. Then I want to set the textField size to fill the old "normal" titleView.
I can't seem to be able to do this in storyBoard. Dragging a text Field to the place where the navigation title View is doesn't work.
So I added stuff at
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
PO(self.navigationItem.titleView);
CGRect theFrame= self.navigationItem.titleView.frame;
self.navigationItem.titleView=self.searchBar;
//self.searchBar.frame = theFrame;
while (false);
...
It's working with one cached. That PO is a macro that print the content of the object. Turns out at viewDidAppear, self.navigationItem.titleView is null.
So while I can display the searchBar, I cannot make the searchBar "fill" it's space because I do not know the space is.
I prefer not to hard code it because you know, things may change in the future.
So what should I do?
I once saw codes where rather than setting the self.navigationItem.titleView, you would simply add subview to it. The problem with this approach even on viewDidAppear, self.navigationItem.titleView is 0.
I added these codes:
CGRect theFrame= self.navigationItem.titleView.frame;
CGRect theFrame2 = self.searchBar.frame;
CGRect theFrame3 = self.navigationController.navigationItem.titleView.frame;
And, I do not know how to nslog structure value, however, theFrame and theFrame3 are all 0
You can try this inside viewWillAppear:
UIView *customTitleView = [[UIView alloc]initWithFrame:CGRectMake((320-210)/2, 0, 210, 50)];
customTitleView.backgroundColor = [UIColor clearColor];
//create your UITextField or UILabel or other view and add as subview of customTitleView
self.navigationItem.titleView = customTitleView;
I use an OHAttributedLabel called demoLbl for displaying text with formatted areas. This label is laid out with Interface Builder and is connected to a property in my ViewController. After setting the attributedText to the label I want all the text to be displayed in the label.
If I don't resize the label then the text is cropped at the end of the label so the rest of the text is missing.
If I use [demoLbl sizeToFit]; then the height of the label is larger or smaller in height than the text (about 10 point, varying with the text's length) thus giving me blank areas at the bottom of my view (after scrolling) plus the width of the label is increased by about 2 points.
If I calculate the height of the original text (NSString) before putting it in a NSAttributedString and adding it to the label's attributedText property then the calculated height is way too small for setting it as the label's height.
Is there a hack or trick I can apply so that the label's height is adjusted according to the NSAttributedString's height?
PS: To be more specific I wanted to add OHAttributedLabel as a tag but it's not allowed to me yet.
I'm the author of OHattributedLabel.
I made some fixes recently about my computation of the size. Please check it out it will probably solve your issue.
I also added a method named sizeConstrainedToSize:fitRange: in NSAttributedString+Attributes.h that returns the CGSize of a given NSAttributedString (quite the same way UIKit's sizeWithFont:constrainedToSize: works, but for Attributed strings and CoreText and not plain stings an UIKit)
Actually OHAttributedLabel's sizeThatFits: calls this method itself now.
You can see if this category gives you a more reliable height.
https://gist.github.com/1071565
Usage
attrLabel.frame.size.height = [attrLabel.attributedString boundingHeightForWidth:attrLabel.frame.size.width];
I added this code to the implementation of the OHAttributedLabel class:
// Toni Soler - 02/09/2011
// Overridden of the UILabel::sizeToFit method
- (void)sizeToFit
{
// Do not call the standard method of the UILabel class, this resizes the frame incorrectly
//[super sizeToFit];
CGSize constraint = CGSizeMake(self.frame.size.width, 20000.0f);
CGRect frame = self.frame;
frame.size = [self sizeThatFits:constraint];
[self setFrame:frame];
}
// End Toni Soler - 02/09/2011
Thank you Olivier for sharing your code!