how to get ios device screen size in a kmp project

Question

I'm an android developer in my kmp project I need the screen size :

expect object ScreenSize {
     val heightDp: Float
}

in android platform i implemented it like this :

actual object ScreenSize {
    actual val heightDp: Float
        get() = Resources.getSystem().displayMetrics.run { heightPixels / density }
}

in ios platform :

actual object ScreenSize {
    actual val heightDp: Float
        get() = UIScreen.mainScreen.bounds.size.height.toFloat
}

as i searched the above code should work but the .height is not known and is red and i can't get the width/height from the UIScreen.mainScreen.bounds.size

Dreaght · Accepted Answer · 2025-04-28 11:22:20Z

1

Solution for your code:
(I have included optional getters for other people too.)

import kotlinx.cinterop.ExperimentalForeignApi
import kotlinx.cinterop.useContents
import platform.UIKit.UIScreen

@OptIn(ExperimentalForeignApi::class)
actual object ScreenSize {
    actual val widthDp: Float
        get() = UIScreen.mainScreen.bounds.useContents { size.width.toFloat() }

    actual val heightDp: Float
        get() = UIScreen.mainScreen.bounds.useContents { size.height.toFloat() }

    actual val density: Float
        get() = UIScreen.mainScreen.scale.toFloat()
}

I faced the the same issue today. You must use useContents {}

Tested on iOS, it correctly returns density now. If you multiply heightDp * scale (density) you will get a real screen pixel height.

edited Apr 28 at 11:22

answered Apr 28 at 11:01

Dreaght

112 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

sepideh Apr 28 at 11:52

it worked thank you

Collectives™ on Stack Overflow

how to get ios device screen size in a kmp project

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related