Create UILabel programmatically and set its position - ios

I want to create a UILabel programmatically from a button click and set its position to the x,y coordinates: (50,50).
The text size can vary between 300 characters to 2,000 characters so I'm using:
[myLabel sizeToFit]
to set the width and height of the label.
This is my code so far:
- (IBAction)createLabel:(id)sender { //create label on button click
UILabel *label;
[label sizeToFit]; //set width and height of label based on text size
//position label
CGRect frame = label.frame;
frame.origin = CGPointMake(50, 50);
label.frame = frame;
label.numberOfLines = 0;
label.lineBreakMode = NSLineBreakByCharWrapping;
label.text = #"This is where the text goes";
[self.view addSubview:label]; //add label to view
}
It doesn't give me any errors when I run the program, but when I press the button to create a label, nothing shows up.

You're not actually creating a label.
UILabel *label;
Just declares a variable, you never initialise it or assign a value to it. You either need a reference to an existing label or you need to create one using initWithFrame:
Also, sizeToFit should be done after you've assigned the text.

Related

UIScrollView not working like most scroll views

I am trying to make my scroll view get to the bottom of my text without having to 'force scroll'. So when I scroll down, the scroll bar at the right stops before I reach the bottom portion of the remaining text. I have to then scroll again with force (so that the scroll bar at the right shrinks, revealing the remaining text). Hopefully someone has encountered this. I don't want to force scroll. I want it all displayed in a clean way.
UIScrollView *theScroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 568.0f)];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(17.0f, 150.0f, 286.0f, 568.0f)];
label.text = #" a very large portion of text ";
label.backgroundColor = [UIColor clearColor];
label.font = [UIFont fontWithName:#"Chalkduster" size:16.0];
label.lineBreakMode = NSLineBreakByWordWrapping;
label.numberOfLines = 0;
[label sizeToFit];
[theScroll setShowsVerticalScrollIndicator:NO];
theScroll.contentSize = CGSizeMake(theScroll.contentSize.width, label.frame.size.height);
[theScroll addSubview:label];
[self.view addSubview:theScroll];
This is all in the viewDidLoad method.
Two things don't quite seem right.
You set the label's origin.y to 150. Did you mean to have the label start so far from the top of the scroll view's content area?
You set the scroll view's contentSize.height to be the same as the label's height. This conflicts with #1. The contentSize.height should be tall enough for all of the content.
Assuming #1 is correct, #2 should be set as:
theScroll.contentSize = CGSizeMake(theScroll.contentSize.width, CGRectGetMaxY(label.frame));
Remember, the bottom of the label will be its origin + its height, not just its height.

Vertical Shift UILabel Text Without Affecting Background

I've been trying to figure out how to vertically align my UILabel text to the top or bottom. The problem is, I have an image behind it which also gets shifted with the text.
Is there a way to keep the background color/image in place, but only shift the text up or down?
Here's the current code:
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (!self) return nil;
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0,
0,
frame.size.width,
frame.size.height)];
label.textAlignment = NSTextAlignmentLeft;
label.font = [UIFont fontWithName:#"AvenirNext-Bold" size:12];
label.backgroundColor = [UIColor clearColor];
[self addSubview:label];
self.numberLabel = label;
self.layer.cornerRadius = 3;
return self;
}
I've been following this tutorial, but it shifts everything, including my label background.
Vertically align text to top within a UILabel
find the height of the text.
Use another view to show image.
Set frame of label relative image view with height of the text and whatever position you want to set for label.
ON the label if you're not using auto layout use:
[YOUR_LABEL sizeToFit];
This will resize your label to fit the text.
What is the background image ? A separate UIImageView ? How are you setting this image ?

Width of UILabel created programmatically

I'm trying to create a UILabel programmatically that fits it's content.
The best I could do was to use the NSString's method sizeWithAtributes to get it's content's required width and then apply a constraint that fixes the width to that value.
Is this the way it is supposed to be done using autolayout?
if you need some with aoutolayouts, i try comment:
UILabel *testLabel = [UILabel new];
[testLabel setFont:[UIFont systemFontOfSize:16]];
[testLabel setText:#"Test text for size context"];
[testLabel setTextAlignment:NSTextAlignmentLeft];
[testLabel setNumberOfLines:0]; //0 - infiniy lines if not enough space more
[testLabel setContentHuggingPriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal]; // Autolayout rule: The higher the priority, the more important hold the text.. by horizontal
[testLabel setContentHuggingPriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisVertical];//some like above but verticale
[testLabel setContentCompressionResistancePriority:UILayoutPriorityDefaultLow forAxis:UILayoutConstraintAxisHorizontal];// reverse like Hugging but Compression. then lower priority then text croping.
[testLabel setContentCompressionResistancePriority:UILayoutPriorityDefaultLow forAxis:UILayoutConstraintAxisVertical];
[testLabel preferredMaxLayoutWidth:200];//Start new line each 200 points width
[testLabel setPreferredMaxLayoutWidth:YES];// resize Font size by label size.
[testLabel setTranslatesAutoresizingMaskIntoConstraints:NO]; // Disable autolaresize, enable autolayouts
At First read the best answer for any question about UILabel
And also by using following code you can create dynamic size of UILabel
UILabel *myLabelName = [[UILabel alloc] init];
myLabelName.backgroundColor = [UIColor redColor];
[myLabelName setFont: [UIFont fontWithName:#"OpenSans" size:13]]; // set font and it's size as per your requirement.
myLabelName.textAlignment = NSTextAlignmentLeft;
myLabelName.frame = CGRectMake(lblComplainTitle.frame.origin.x + lblComplainTitle.frame.size.width + 7, lblComplainTitle.frame.origin.y +2, 160, 20);
myLabelName.text = #"This is my testing text, This is my testing text, This is my testing text, This is my testing text, This is my testing text, This is my testing text, This is my testing text, This is my testing text, This is my testing text, This is my testing text.";
myLabelName.textColor = [UIColor blackColor];
[self setDynamicHeightOfLabel:myLabelName withLblWidth:160 andFontSize:13]; // here in this function you need to pass object of label with width (as you wabt) and font size
[self.view addSubview:myLabelName];
Code of function, name is setDynamicHeightOfLabel:withLblWidth:andFontSize
-(void) setDynamicHeightOfLabel:(UILabel *) myLabel withLblWidth:(CGFloat) width andFontSize:(int) fontSize
{
CGSize myLabelSize = CGSizeMake(width, FLT_MAX);
CGSize expecteingmyLabelSize = [myLabel.text sizeWithFont:myLabel.font constrainedToSize:myLabelSize lineBreakMode:myLabel.lineBreakMode];
CGRect lblFrame = myLabel.frame;
lblFrame.size.height = expecteingmyLabelSize.height;
myLabel.frame = lblFrame;
int addressLine = myLabel.frame.size.height/fontSize;
myLabel.numberOfLines = addressLine;
}
I create function because you can create any label with dynamic size without use of repeated code.
There is a couple of steps that you have to do to achieve this using autolayout.
Set layout constrains for the label.
Set height constraint with low priority.
Set numberOfLines to 0 to allow multiline text.
Set preferredMaxLayoutWidth for the label.
The preferredMaxLayoutWidth is used by label to calculate its height.
This property affects the size of the label when layout constraints
are applied to it. During layout, if the text extends beyond the width
specified by this property, the additional text is flowed to one or
more new lines, thereby increasing the height of the label.
Hi you can manage the width of lable by doing so programatically,
CGRect frame;
frame =self.yourLabel.frame;
frame.size.width +=20;
self.yourLabel.frame=frame;
Thanks

Clipping of UILabel when adjustsFontSizeToFitWidth

When I add text to a label with the adjustsFontSizeToFitWidth set to YES the text is no longer centred vertically and eventually clips the text at the bottom of the label frame. For a large amount of text it will eventually disappear off the bottom of the label.
This is what happens if you add less text:
This is clipped as I would expect it (i.e. the font size did not reduce, the text was vertically centred in the label and clipped on the top and bottom.
Here is the code to reproduce:
- (void)loadView {
[super loadView];
self.view.backgroundColor = [UIColor blueColor];
testLabel = [[UILabel alloc] init];
testLabel.font = [UIFont boldSystemFontOfSize:172];
testLabel.textColor = [UIColor blackColor];
testLabel.adjustsFontSizeToFitWidth = YES;
testLabel.numberOfLines = 1;
testLabel.frame = CGRectMake(50, 50, 300, 100);
testLabel.text = #"123";
[self.view addSubview:testLabel];
}
Should this happen? And how do I get my label to centre vertically irrespective of the number of characters in my label.
Add
testLabel.baselineAdjustment = UIBaselineAdjustmentAlignCenters;
to your code to vertical-center the text on font scale.
Would also like add that adjustsFontSizeToFitWidth doesn't work too well with attributed text, so add your attributes to the label instead of the attributed text if you can. This worked for me.

Positioning UILabel inside a UITextView

Trying to position a UILabel above some text, but the elements are "stepping" on each other. I positioned them with x,y,h,w such that they should not do this but alas, they are. You can see in the screenshot that the label text "Abalone" and the text are commingled. What changes do I need to make here? I've already tried changing the x,y,w,h values to no great effect...
txtView = [[UITextView alloc] initWithFrame:CGRectMake(10,20,280,300)];
[txtView setFont:[UIFont fontWithName:#"ArialMT" size:14]];
txtView.text = word.definition;
txtView.editable = NO;
txtView.scrollEnabled = YES;
[txtView scrollRangeToVisible:NSMakeRange([txtView.text length], 0)];
txtView.minimumZoomScale = 1;
txtView.maximumZoomScale = 10;
UILabel *wordTitle = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 250, 20)];
wordTitle.text = word.term;
[txtView addSubview:wordTitle];
[detailsViewController.view addSubview:txtView];
I think the problem is you are adding the label view as a subview to UITextview. You have to reserve some space for the label view in the UITextview. You can either add some padding to the textView, which can be confusing, because padding in UITextView is not constant and varies based on the font size. Or you can add your UILabel directly to the detailsViewController.view and start your UITextView below the label.
Hope it helps.

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