iOS get physical screen size programmatically?

Question

Is this possible? I want the number of inches, not the number of pixels. I know it is approximately 160 ppi. But not exactly.

Answer 1

There isn't an API that will give you this. Your best bet is to look at the device's screen size (in points) and from that surmise if it's an iPad or iPhone etc., and then use hard-coded values for the screen sizes.

Here's some code to get the screen size:

CGRect screenRect = [[UIScreen mainScreen] bounds];
CGFloat screenWidth = screenRect.size.width;
CGFloat screenHeight = screenRect.size.height;

Be aware that width and height might be swapped, depending on device orientation.

Answer 2

If it were available it would be in UIScreen or UIDevice but it is not there.

You can infer it from info in Erica's UIDevice-extension and the specs for each device listed here on Wikipedia .

Answer 3

Here's a short method that estimates the device screen size. It's updated as to the latest devices, but may fail on future ones (as all methods of guessing might). It will also get confused if the device is being mirrored (returns the device's screen size, not the mirrored screen size)

#define SCREEN_SIZE_IPHONE_CLASSIC 3.5
#define SCREEN_SIZE_IPHONE_TALL 4.0
#define SCREEN_SIZE_IPAD_CLASSIC 9.7

+ (CGFloat)screenPhysicalSize
{
    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {
        CGSize result = [[UIScreen mainScreen] bounds].size;
        if (result.height < 500)
            return SCREEN_SIZE_IPHONE_CLASSIC;  // iPhone 4S / 4th Gen iPod Touch or earlier
        else
            return SCREEN_SIZE_IPHONE_TALL;  // iPhone 5
    }
    else
    {
        return SCREEN_SIZE_IPAD_CLASSIC; // iPad
    }
} 

Answer 4

You might need use [UIScreen mainScreen].scale;

CGFloat scale = [UIScreen mainScreen].scale;
CGRect screenRect = [[UIScreen mainScreen] bounds];

CGFloat physicalWidth = screenRect.size.width * scale;
CGFloat physicalHeight = screenRect.size.height * scale;

Answer 5

Since this question has been asked, I've created an open-source library to handle this problem: IRLSize . It can be used in either direction: to measure the size of a view (or the whole screen) in real-world dimensions, or to set the size of a view to a specific real-world dimension.

Answer 6

Maybe Jeff Hay's code can be adapted to include iPad Mini. The trick is to get the device's model identifier. The most recent non-retina iPad is "iPad2,4" and the first iPad mini is "iPad2,5". Now all you need to check is if the screen scaling is 1.0 (non-retina)

Although this code is not future-proof, you can always add more rules for model identifiers.

#import <sys/utsname.h>

#define SCREEN_SIZE_IPAD_MINI 7.9

    struct utsname systemInfo;
    uname(&systemInfo);
    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad && strcasecmp(systemInfo.machine, "iPad2,5") >= 0 [[UIScreen mainScreen] scale] == 1.0)
        return SCREEN_SIZE_IPAD_MINI

Answer 7

我使用的“公式”是

#define IS_iPhone5 ( fabs( (double)[ [ UIScreen mainScreen ] bounds ].size.height - (double)568 ) < DBL_EPSILON )

Answer 8

note: screen rotation matters here

extension UIScreen {
    var physicalSize:CGSize {
        return CGSize(width: bounds.width*scale, height: bounds.height*scale)
    }
}

using:

print(UIScreen.main.physicalSize)

Answer 9

Here is a Swift way to get screen sizes:

var screenWidth: CGFloat {
    if UIInterfaceOrientationIsPortrait(screenOrientation) {
        return UIScreen.mainScreen().bounds.size.width
    } else {
        return UIScreen.mainScreen().bounds.size.height
    }
}
var screenHeight: CGFloat {
    if UIInterfaceOrientationIsPortrait(screenOrientation) {
        return UIScreen.mainScreen().bounds.size.height
    } else {
        return UIScreen.mainScreen().bounds.size.width
    }
}
var screenOrientation: UIInterfaceOrientation {
    return UIApplication.sharedApplication().statusBarOrientation
}

These are included as a standard function in:

https://github.com/goktugyil/EZSwiftExtensions

Answer 10

Nobody said about fixedCoordinateSpace . In Swift 3 to get the screen dimensions in a portrait-up orientation you should use: UIScreen.main.fixedCoordinateSpace.bounds

Answer 11

CGFloat scale = [UIScreen mainScreen].scale; CGRect screenRect = [[UIScreen mainScreen] bounds]; CGFloat screenWidth = screenRect.size.width * (scale/100.0f); CGFloat screenHeight = screenRect.size.height * (scale/100.0f);

• 规模是存在的！