in iPhone App How to detect the screen resolution of the device

In iPhone App, while running the App on device 开发者_如何学CHow to detect the screen resolution of the device on which App is running?

CGRect screenBounds = [[UIScreen mainScreen] bounds];

That will give you the entire screen's resolution in points, so it would most typically be 320x480 for iPhones. Even though the iPhone4 has a much larger screen size iOS still gives back 320x480 instead of 640x960. This is mostly because of older applications breaking.

CGFloat screenScale = [[UIScreen mainScreen] scale];

This will give you the scale of the screen. For all devices that do not have Retina Displays this will return a 1.0f, while Retina Display devices will give a 2.0f and the iPhone 6 Plus (Retina HD) will give a 3.0f.

Now if you want to get the pixel width & height of the iOS device screen you just need to do one simple thing.

CGSize screenSize = CGSizeMake(screenBounds.size.width * screenScale, screenBounds.size.height * screenScale);

By multiplying by the screen's scale you get the actual pixel resolution.

A good read on the difference between points and pixels in iOS can be read here.

EDIT: (Version for Swift)

let screenBounds = UIScreen.main.bounds
let screenScale = UIScreen.main.scale
let screenSize = CGSize(width: screenBounds.size.width * screenScale, height: screenBounds.size.height * screenScale)

UIScreen class lets you find screen resolution in Points and Pixels.

Screen resolutions is measured in Points or Pixels. It should never be confused with screen size. A smaller screen size can have higher resolution.

UIScreen's 'bounds.width' return rectangular size in Points

UIScreen's 'nativeBounds.width' return rectangular size in Pixels.This value is detected as PPI ( Point per inch ). Shows the sharpness & clarity of the Image on a device.

You can use UIScreen class to detect all these values.

Swift3

// Normal Screen Bounds - Detect Screen size in Points.
let width = UIScreen.main.bounds.width
let height = UIScreen.main.bounds.height
print("\n width:\(width) \n height:\(height)")

// Native Bounds - Detect Screen size in Pixels.
let nWidth = UIScreen.main.nativeBounds.width
let nHeight = UIScreen.main.nativeBounds.height
print("\n Native Width:\(nWidth) \n Native Height:\(nHeight)")

Console

width:736.0 
height:414.0

Native Width:1080.0 
Native Height:1920.0

Swift 2.x

//Normal Bounds - Detect Screen size in Points.
    let width  = UIScreen.mainScreen.bounds.width
    let height = UIScreen.mainScreen.bounds.height

// Native Bounds - Detect Screen size in Pixels.
    let nWidth  = UIScreen.mainScreen.nativeBounds.width
    let nHeight = UIScreen.mainScreen.nativeBounds.height

ObjectiveC

// Normal Bounds - Detect Screen size in Points.
CGFloat *width  = [UIScreen mainScreen].bounds.size.width;
CGFloat *height = [UIScreen mainScreen].bounds.size.height;

// Native Bounds - Detect Screen size in Pixels.
CGFloat *width  = [UIScreen mainScreen].nativeBounds.size.width
CGFloat *height = [UIScreen mainScreen].nativeBounds.size.width

Use it in App Delegate: I am using storyboard

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {

    CGSize iOSDeviceScreenSize = [[UIScreen mainScreen] bounds].size;

    //----------------HERE WE SETUP FOR IPHONE 4/4s/iPod----------------------

    if(iOSDeviceScreenSize.height == 480){          

        UIStoryboard *iPhone35Storyboard = [UIStoryboard storyboardWithName:@"iPhone" bundle:nil];

        // Instantiate the initial view controller object from the storyboard
        UIViewController *initialViewController = [iPhone35Storyboard instantiateInitialViewController];

        // Instantiate a UIWindow object and initialize it with the screen size of the iOS device
        self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

        // Set the initial view controller to be the root view controller of the window object
        self.window.rootViewController  = initialViewController;

        // Set the window object to be the key window and show it
        [self.window makeKeyAndVisible];

        iphone=@"4";

        NSLog(@"iPhone 4: %f", iOSDeviceScreenSize.height);

    }

    //----------------HERE WE SETUP FOR IPHONE 5----------------------

    if(iOSDeviceScreenSize.height == 568){

        // Instantiate a new storyboard object using the storyboard file named Storyboard_iPhone4
        UIStoryboard *iPhone4Storyboard = [UIStoryboard storyboardWithName:@"iPhone5" bundle:nil];

        // Instantiate the initial view controller object from the storyboard
        UIViewController *initialViewController = [iPhone4Storyboard instantiateInitialViewController];

        // Instantiate a UIWindow object and initialize it with the screen size of the iOS device
        self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

        // Set the initial view controller to be the root view controller of the window object
        self.window.rootViewController  = initialViewController;

        // Set the window object to be the key window and show it
        [self.window makeKeyAndVisible];

         NSLog(@"iPhone 5: %f", iOSDeviceScreenSize.height);
        iphone=@"5";
    }

} else if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
    // NSLog(@"wqweqe");
    storyboard = [UIStoryboard storyboardWithName:@"iPad" bundle:nil];

}

 return YES;
 }

For iOS 8 we can just use this [UIScreen mainScreen].nativeBounds , like that:

- (NSInteger)resolutionX
{
    return CGRectGetWidth([UIScreen mainScreen].nativeBounds);
}

- (NSInteger)resolutionY
{
    return CGRectGetHeight([UIScreen mainScreen].nativeBounds);
}

See the UIScreen Reference: http://developer.apple.com/library/ios/#documentation/uikit/reference/UIScreen_Class/Reference/UIScreen.html

if([[UIScreen mainScreen] respondsToSelector:NSSelectorFromString(@"scale")])
{
    if ([[UIScreen mainScreen] scale] < 1.1)
        NSLog(@"Standard Resolution Device");

    if ([[UIScreen mainScreen] scale] > 1.9)
        NSLog(@"High Resolution Device");
}

Use this code it will help for getting any type of device's screen resolution

 [[UIScreen mainScreen] bounds].size.height
 [[UIScreen mainScreen] bounds].size.width

If your goal is to get the model resolution type and not the resolution values themeselfs, this Swift solution might be helpful:

import UIKit

@objc(IphoneModelScreenSize)
public class IphoneModelScreenSize: NSObject {

    // MARK: Enums

    public enum IphoneModelScreenSize: Int {
    case notAnIphone = 0,
         twoThreeOrFour = 1,
         se = 2,
         sixSevenOrEight = 3,
         plus = 4,
         elevenXorXS = 5,
         elevenProMaxOrXsMax = 6
    }

    // MARK: Class properties

    public class func screenSize() -> IphoneModelScreenSize {
        let bounds = UIScreen.main.bounds
        let screenWidth = bounds.size.width
        let screenHeight = bounds.size.height

        switch (screenWidth, screenHeight) {
        case (320.0, 480.0):
          return .twoThreeOrFour
        case (320.0, 568.0):
          return .se
        case (375.0, 667.0):
          return .sixSevenOrEight
        case (414.0, 736.0):
          return .plus
        case (375.0, 812.0):
          return .elevenXorXS
        case (414.0, 896.0):
          return .elevenProMaxOrXsMax
        default:
          return .notAnIphone
        }
    }

    public class func screenSizeStringValue() -> String {
        return screenSizeEnumToString(screenSize())
    }

    // MARK: Private properties

    private class func screenSizeEnumToString(_ screenSize: IphoneModelScreenSize) -> String {
        var screenSizeAsString: String

        switch screenSize {
        case .notAnIphone:
            screenSizeAsString = "Not an Iphone"
        case .twoThreeOrFour:
            screenSizeAsString = "2G, 3G, 3GS, 4 or 4s"
        case .se:
            screenSizeAsString = "5, 5s, 5c or SE"
        case .sixSevenOrEight:
            screenSizeAsString = "6, 6s, 7 or 8"
        case .plus:
            screenSizeAsString = "6+, 6s+, 7+ or 8+"
        case .elevenXorXS:
            screenSizeAsString = "11 Pro, X or Xs"
        case .elevenProMaxOrXsMax:
            screenSizeAsString = "11, Xr, 11 Pro Max or Xs Max"
        }

        return screenSizeAsString
    }

}