Do the UI elements in Xamarin scale automatically? - xamarin

Do the UI elements in Xamarin scale automatically with different screen resolutions or do I have to do something?

It really depends what type of project you use and how you make your UI.
If you are using Xamarin.Forms you can set height and width requests, that should scale with resolution.
If you are using classic Xamarin.iOS and Xamarin.Android projects, each of the underlying platforms have ways to scale views on different screen sizes. Most of the time, if you are not using fixed widths and heights views should scale fine.
In both cases, make sure to provide correctly sized image assets for icons etc.

Related

Xcode auto alignment and constraints - equal distances between several images

I have nine images ad I want them to display in a single column on the device. The images should retain their original height and width (that I will set) and the only thing that should change according to the screen height should be the distance between the images.
I'm not really sure how to approach this problem - I tried using a container, but it didn't turn out as I expected. Should I set the constraints programmatically? And if so, how? What should the constraints be if I want the images to be from top to bottom of he screen?
Consider using a stack view:
On iOS, UIStackView provides UIStackViewDistributionEqualSpacing, which I believe will arrange images as you want
On Mac, NSStackView can automatically space images as you describe if the individual image views are all in the same gravity and retain their sizes at a high enough priority (using constraints or content hugging priority)

How do GUI developers deal with variable pixel densities?

Todays displays have a quite huge range in size and resolution. For example, my 34.5cm × 19.5cm display (resulting in a diagonal of 39.6cm or 15.6") has 1366 × 768 pixels, whereas the MacBook Pro (3rd generation) with a 15" diagonal has 2880×1800 pixels.
Multiple people complained that everything is too small with such high resolution displays (see example). That is simple to explain when developers use pixels to define their GUI. For "traditional displays", this is not a big problem as the pixels might have about the same size on most monitors. But on the new monitors with much higher pixel density the pixels are simply smaller.
So how can / should user interface developers deal with that problem? Is it possible to get the physical size of the screen? Is it possible to set physical sizes instead of pixel-based ones? Is that still a problem (it's been a while since I last read about it) or was that fixed meanwhile?
(While css seems to support cm, when I try here it, it is not the set size).
how can / should user interface developers deal with that problem?
Use a toolkit or framework that support resolution independence. WPF is built from the ground up to be resolution-independent, but even old framework like Windows Forms can learn new tricks. OSX/iOS and Windows (or browser if we're talking about web) itself may try to take care the problem by automatic scaling, but if there's bitmap graphic involved, developers might need to provide different bitmaps such in Android (which face most varying resolution and densities compared to other OS)
Is it possible to get the physical size of the screen?
No, and developers shouldn't care about it. Developers should only care about the class of the device (say, different UI for tablet and smartphone), and perhaps the DPI to decide which bitmap resource to use. Vector resource and font should be scaled by the framework.
Is that still a problem (it's been a while since I last read about it) or was that fixed meanwhile?
Depend on when you last read about it. Windows support is still spotty, even for the internal apps itself, and while anyone developing in WPF or UWP have it easy, don't expect major third party apps to join soon. OSX display scaling seems to work a bit better, while modern mobile OS are either running on limited range of resolution (iOS and Windows Phone) or handle every resolution imaginable quite nicely (Android)
There are a few ways to deal with different screen sizes, for example when I make mobile apps in java, I either use DIP(Density Independent Pixels; They stay at a fixed size) or make objects occupy a percentage of the screen with simple math. As for web development, you can use VW and VH (Viewport Width and Viewport Height), by adding these to the end of a value instead of px, the objects take up a percentage of the viewport. For example 100vh takes 100% of the viewport height. Then what I think is the best way to do it, but time consuming, is to use a library like Bootstrap that automatically resizes elements, even when the window is resized. W3Schools has a good tutorial on bootstrap and more detailed explainations on any of these options can be looked up with an easy google search.
The design of the GUI in today display diversity era is real challenge. I would suggest several hints, mainly about the GUI applications design:
Never set or expect constant pixel size of the text - the user can change it from the system settings of the OS. Use some real-world measures for the text and check its pixel size when drawing. Provide some way to put the random size text in the boundaries of the window.
Never set or expect constant pixel size of the GUI widgets. Try to position them on the window in some adaptive way - according to the size of the window. Most GUI widget toolkits today have such instruments.
Never set or expect constant pixel size dialog windows. Let the OS to choose the size for you and then use what you get (X). Or, if you need to set some size and position (Windows), define it as a percent of the screen size.
If possible use scalable image formats for the icons. SVG is great for icons actually. Using sets of bitmap icons with different sizes is acceptable, but highly non-optimal as memory use and still will not provide perfect scaling in most cases.

Bootstrap Carousel image height causes scroll bars on smaller screens

I'm very new to bootstrap, and programming in general so please be patient! I have literally spent hours trying to find a solution to my problem via here/google, and the time has come to ask for some help!
Basically, I am trying to make a website for displaying photos in a carousel. I want my site to be responsive so it works on smaller devices. All my original images are the same size/dimensions (2304 x 1728 so 4:3, probably too big) and use the img-responsive class.
It looks fine on a large screen, but when I try it on smaller laptop screens and tablets, the image height causes scrollbars to appear so you can't see the bottom of the image/caption. However, the image width is responsive and shrinks to fit without scrolling.
I am of the understanding that the carousel size is dictated by the image size, so the logical solution would be to make my image size smaller in height - but I need to maintain the aspect ratio, and smaller images didn't look so good. I also tried setting a fixed height as a style but it didn't work.
What is the ideal image size (in px) for a carousel which takes up most of a browser window (allowing for navbar/header/footer), and how do you make it so the height doesn't require scrollbars?
Many thanks in advance!
My answer may not be accepted by everyone , but I think the only flaw of bootstrap is precisely the Bootstrap Carousel
Can not be changed easily (since as you say you do not have much programming experience), and does not offer a lot of customization
So I think the best solution for your problem is Owlcarousel , offers hundreds of customization options
OWL Carousel
Touch enabled jQuery plugin that lets you create beautiful responsive carousel slider.

How to build windows store app for device independent pixel (DIP)

i am building windows store app. I am using windows 8 and WPF with visual studio .net 2012.
UI of this application should be scalable to different screens. I have created a page where the controls (buttons, images, texts) fits correctly when running the app on simulator with resolution 1920 x 1080 for 10.6" screens. The problem is that when i change resolution, controls do not behave correctly
when resolution or screen sizes are increased (ex. 1920 x 1080 for 23" screens) empty spaces are created on the page;
when resolution or screen sizes are decreased (ex. 1024 x 768 for 10.6" screens) controls sizes are increased too and some of them are not visible in UI because they are displayed too far in bottom.
Is there a way to build "scalable" store app which are independent of screen sizes or resolution? Control sizes and font sizes should increase and decrease when resolution change or from one screen to another but all of them should fit in the space and shouldn't create empty areas.
Any help would be very appreciated.
thank you
This MSDN article discusses the guidelines for scaling to screens.
it touches on Screen size, Screen resolution, and Aspect ratio. It provides a table which shows best practices recommended for apps that use scale-to-fit functionality and it touches on adaptive layout. there is a reference to [Guidelines for layouts] at the end of the article as well.
Hope this helps!
http://msdn.microsoft.com/en-us/library/windows/apps/hh780612.aspx
joelcitizen

UI scaling - XNA

(Sorry if I missed the answer)
So I just started out making an XNA game for windows.
And while designing the UI, I was wondering how to scale the UI at different resolutions.
So, imagine that I make a UI for a 1920*1080 screen, how do I make sure this is displayed correctly on a smaller 4*3 screen?
Thanks in advance!
Simon.
Usually one designs the GUI in a way that will be usable in the lowest resolution your game offers (traditionally 800x600), then you are sure everything fits correctly at all resolutions.
This is usually why games at higher resolutions seem to have a lot more space for the "playfield" and less for UI than at smaller resolutions.
You could scale the UI once the resolution is higher as well, as easy as using the scale parameter on SpriteBatch.Draw, or you could do it a bit more smartly, by having your assets 9-sliced and aligned to WIDTH/HEIGHT constant percentages.

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