how to get the dimensions of custom image on storyboard manually - ios

I added a custom UIImageView to a storyboard and got the following dimensions:
I tried using CGRectMake(170, 115, 260, 200) in my code to crop an image but didn't get the same dimensions as the UIImageView, but a size considerably smaller than that used in the storyboard. How can I get the exact dimensions for a CGRect?

I think you are confused between what things look like in storyboard vs on the device. The storyboard only is a representation of a set of rules that will dictate how things will appear on actual devises.
If you want the UIImageView to be the same size on all devises you need to set constraints for height and width
If you want the same ratio to prevent your image from distorting you need to set ratio constraints
You should read this: ray auto layout tutorial
In case this does not help, this is how you get the size of a CGRect:
CGRect myFrame = [YOUR_VIEW frame];
NSLog(#"height = %f", myFrame.size.height);
NSLog(#"width = %f", myFrame.size.width);
NSLog(#"x = %f", myFrame.origin.x);
NSLog(#"y = %f", myFrame.origin.y);

Related

bounds of imageView are always 240

I have a probably simple mistake that drives me crazy.
I'm working with UIImageView within a UIScrollView. To fit the image in the view I want to get the width of the imageView to adjust the zoom scale.
But the code
imageView.bounds.width
always returns 240.0 no matter what size the actual image has.
In the Interface Builder the imageView is horizontally and verically centered in the view, clip subviews is true and Mode is aspect fit.
Any ideas?
The size of the UIImageView is not related to the size of the image it contains. The UIImageView is probably sized to 240.0 in the storyboard or wherever else you generate it. The image will scale down or up to fit the view based on the mode. To get the size of the actual image, try the following code:
let image = UIImage("my_image_file")
let imageHeight = image.size.height
let imageWidth = image.size.width
With the size of the image now know, you can set the size of the view appropriately.
I had the same problem. Now I check the bounds in the main_queue and everything works fine.
dispatch_async(dispatch_get_main_queue(), {
print(self.image.bounds.width)
})

Create non-constant width for UILabel in Interface Builder using Auto Layout

I have an existing UILabel that I created in Interface Builder, I would like to change its width in code, but I can't because of the auto layout. It's pretty simple, I have width from a CGSize and I wanna set it for the label. Actually my code works perfectly, I can assign the new size to the label, but unfortunately it doesn't redrawn itself. I've tried to use the textRectForBounds:limitedToNumberOfLines:and preferredMaxLayoutWidth without any success or size changes.
float heightIs =
[cell.lbl.text
boundingRectWithSize:cell.lbl.frame.size
options:NSStringDrawingUsesLineFragmentOrigin
attributes:#{ NSFontAttributeName:cell.lbl.font }
context:nil]
.size.height;
// get the width size of a string
CGSize textSize = [cell.lbl.text sizeWithAttributes:#{NSFontAttributeName:cell.lbl.font}];
CGFloat strikeWidth = textSize.width;
NSLog(#"TEXT WIDTH %f OF STRING %#", strikeWidth, nameString);
CGRect labelFrame = CGRectMake (0, 0, strikeWidth, heightIs);
cell.lbl.frame = labelFrame;
cell.lbl.preferredMaxLayoutWidth = CGRectGetWidth(labelFrame);
NSLog(#"LABEL WIDTH VALUE %f", cell.lbl.frame.size.width);
Could somebody explain me the right way? I'm not sure that where should I start it. Is it an option somewhere in IB or can I do it with code? Or I can delete all code because it can be done only with IB?

UIImageView with fixed width: how to set its height to keep its aspect?

I have a view where I need to place an UIImageView, and I was told to place it inside a rectangle that takes the screen width and its height is smaller than width (fixed size). However, the images I've been given are more or less square jpeg images, so the idea is to fill the width of the rectangle that should contain the image and set the height of the image in a way that its aspect ratio is kept. Then, I should be able to let the user scroll the image vertically to see the complete image.
How could I do this?
Thanks in advance
EDIT: I need to do this for several images that have different sizes, but that should fit the same rectangular area size within the view
You can set imageview content mode.
imageView.contentMode = UIViewContentModeScaleAspectFit;
This will make sure that the image is displayed by keeping original aspect ratio.
Edit:
I think this is what you wanted:
UIImage *originalImage = [UIImage imageNamed:[picArr objectAtIndex:a]];
double width = originalImage.size.width;
double height = originalImage.size.height;
double apect = width/height;
double nHeight = 320.f/ apect;
self.img.frame = CGRectMake(0, 0, 320, nHeight);
self.img.center = self.view.center;
self.img.image = originalImage;
Hope this helps.. :)

Programmatically create subview that covers the top 50% of the iPhone screen

I have a subview and I have been customizing its size by using the frame property and setting its value to the CGRectMake function's parameter values.
I have slowly but surely been changing the CGRectMake parameters and re-running the app to get the subview to the correct position on the screen but I know there has to be an easier way.
Here is what I am currently doing:
UIImageView *halfView = [[UIImageView alloc]initWithImage:image];
[self.view addSubview:halfView];
halfView.frame = CGRectMake(0, 0, 320, 270);
Is there a way that I can stop having to manually enter those 4 parameters into CGRectMake, and just set it to the top 50% of the screen?
Here is what I want the subview to look like on the iphone's screen:
halfView.frame = CGRectMake(0, 0, 320, self.view.bounds.size.height/2);
you just take the height and divide it by two
You should also probably change 320 to self.view.bounds.size.width
I suggest reading this post to really get a grasp of UIViews and working with them:
UIView frame, bounds and center

Make an UIImageView and its UIImage scale proportionally without extra padding

I have an UIView that contains a UIImageView. The UIImageViews works like the branding logo of the app. When I rotate the device, the containing UIView resizes itself to correspond to the landscape or portrait proportions of the screen.
What I'm trying to achieve is to have the UIImageView scaled accordingly, keeping proportions also on the left margin.
This is the actual code for the top white "banner":
UIView *topBanner = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, height_topBanner)];
[topBanner setAutoresizingMask:(UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleBottomMargin)];
[topBanner setBackgroundColor:[UIColor whiteColor]];
topBanner.autoresizesSubviews = YES;
// the logo
UIImage *topBanner_logo = [UIImage imageNamed:#"logo.png"];
float logoAspectRatio = topBanner_logo.size.width/topBanner_logo.size.height;
topBanner_logoView = [[UIImageView alloc] initWithFrame:CGRectMake(topBanner.frame.size.width/100*3, topBanner.frame.size.height/100*7, (topBanner.frame.size.height/100*86)*logoAspectRatio, topBanner.frame.size.height/100*86)];
[topBanner_logoView setImage:topBanner_logo];
topBanner_logoView.backgroundColor = [UIColor blueColor];
topBanner_logoView.contentMode = UIViewContentModeScaleAspectFit;
[topBanner_logoView setAutoresizingMask:(UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleBottomMargin|UIViewAutoresizingFlexibleRightMargin)];
[topBanner addSubview:topBanner_logoView];
[self.view addSubview:topBanner];
This is my starting point: portrait iPad on startup:
This is what happens when I rotate it in landscape:
As you can see, the proportions of the UIImage are ok, but I'm getting extra borders (I set the background color of the UIImageView to highlight it) because the UIImageView stretches itself to follow the change of the size of its container, and the UIImage is fit into the UIImageView and put on its center.
The same - reversed - happens when I start the app directly in landscape mode:
Then I rotate it:
... and I get the logo with extra borders on top and bottom.
I do see that I can write a function to recalculate every size on each rotation change, but I'm asking to myself if is there a way to set the UIImageView and the UIImage to make it works without hacking the autorotate/resize procedures of iOS. It sounds so simple!
You can solve this by not using UIViewContentModeScaleAspectFit, and instead calculating the aspect ratio of the image and using that to explicitly the width or height based on the other (width or height).
e.g. I rotate to landscape, and so I want the height to be 80% of the view.
CGFloat w = logo.image.size.width;
CGFloat h = logo.image.size.height;
CGFloat a = w / h;
CGFloat h_use = self.view.height *0.8;
CGFloat w_use = h_use*a;
Furthermore, set the content mode to UIViewContentModeScaleAspectFill instead now that you've explicitly set the aspect ratio.
You have set the auto resizing mask to flexible height and width:
[topBanner_logoView setAutoresizingMask:(UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleBottomMargin|UIViewAutoresizingFlexibleRightMargin)];
If you do not do that, the default is that the view will not chance size, and therefore, the image will not either.
I think it is because of topBanner_logoView.contentMode = UIViewContentModeScaleAspectFit;
Try topBanner_logoView.contentMode = UIViewContentModeCenter or topBanner_logoView.contentMode = UIViewContentModeLeft to prevent the UIImageView's image from resizing (and getting padding).
If the UIImageView is resizing, remove the autoresizing mask.

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