Answers:
如何在iOS中获取屏幕尺寸？
您发布的代码的问题在于您要依靠视图的大小来匹配屏幕的大小，而且正如您所看到的，情况并非总是如此。如果需要屏幕尺寸，则应查看代表屏幕本身的对象，如下所示：
CGRect screenRect = [[UIScreen mainScreen] bounds];
CGFloat screenWidth = screenRect.size.width;
CGFloat screenHeight = screenRect.size.height;拆分视图的更新：在评论中，Dmitry问：
如何在拆分视图中获取屏幕尺寸？
上面给出的代码即使在分屏模式下也报告屏幕的大小。使用分屏模式时，应用程序的窗口会更改。如果上面的代码没有给您期望的信息，那么像OP一样，您正在寻找错误的对象。但是，在这种情况下，您应该查看窗口而不是屏幕，如下所示：
CGRect windowRect = self.view.window.frame;
CGFloat windowWidth = windowRect.size.width;
CGFloat windowHeight = windowRect.size.height;let screenRect = UIScreen.main.bounds
let screenWidth = screenRect.size.width
let screenHeight = screenRect.size.height
// split screen
let windowRect = self.view.window?.frame
let windowWidth = windowRect?.size.width
let windowHeight = windowRect?.size.height[UIScreen scale]。
CGRectGetWidth()而CGRectGetHeight()不是直接访问size矩形中的字段。对于屏幕矩形，我不认为这是个问题，但是我想这是需要注意的事情。
小心[UIScreen mainScreen]也包含状态栏，如果要检索应用程序的框架（状态栏除外），则应使用
+ (CGFloat) window_height {
return [UIScreen mainScreen].applicationFrame.size.height;
}
+ (CGFloat) window_width {
return [UIScreen mainScreen].applicationFrame.size.width;
}return [[UIScreen mainScreen] bounds].size.width;
我已经将上述一些Objective-C答案翻译成了Swift代码。每次翻译都参考原始答案。
let screen = UIScreen.main.bounds
let screenWidth = screen.size.width
let screenHeight = screen.size.heightfunc windowHeight() -> CGFloat {
return UIScreen.mainScreen().applicationFrame.size.height
}
func windowWidth() -> CGFloat {
return UIScreen.mainScreen().applicationFrame.size.width
}var screenHeight : CGFloat
let statusBarOrientation = UIApplication.sharedApplication().statusBarOrientation
// it is important to do this after presentModalViewController:animated:
if (statusBarOrientation != UIInterfaceOrientation.Portrait
&& statusBarOrientation != UIInterfaceOrientation.PortraitUpsideDown){
screenHeight = UIScreen.mainScreen().applicationFrame.size.width
} else {
screenHeight = UIScreen.mainScreen().applicationFrame.size.height
}let screenWidth = UIScreen.mainScreen().bounds.size.width
let screenHeight = UIScreen.mainScreen().bounds.size.height
println("width: \(screenWidth)")
println("height: \(screenHeight)")return UIScreen.mainScreen().bounds].size.width
我之前使用过以下便捷方法：
- (CGRect)getScreenFrameForCurrentOrientation {
return [self getScreenFrameForOrientation:[UIApplication sharedApplication].statusBarOrientation];
}
- (CGRect)getScreenFrameForOrientation:(UIInterfaceOrientation)orientation {
CGRect fullScreenRect = [[UIScreen mainScreen] bounds];
// implicitly in Portrait orientation.
if (UIInterfaceOrientationIsLandscape(orientation)) {
CGRect temp = CGRectZero;
temp.size.width = fullScreenRect.size.height;
temp.size.height = fullScreenRect.size.width;
fullScreenRect = temp;
}
if (![[UIApplication sharedApplication] statusBarHidden]) {
CGFloat statusBarHeight = 20; // Needs a better solution, FYI statusBarFrame reports wrong in some cases..
fullScreenRect.size.height -= statusBarHeight;
}
return fullScreenRect;
} 我意识到这是一篇过时的文章，但是有时我发现#define这样的常量很有用，因此我不必担心：
#define DEVICE_SIZE [[[[UIApplication sharedApplication] keyWindow] rootViewController].view convertRect:[[UIScreen mainScreen] bounds] fromView:nil].size无论设备方向如何，以上常量均应返回正确的大小。然后获取尺寸非常简单：
lCurrentWidth = DEVICE_SIZE.width;
lCurrentHeight = DEVICE_SIZE.height;获取设备尺寸以及考虑方向非常非常容易：
// grab the window frame and adjust it for orientation
UIView *rootView = [[[UIApplication sharedApplication] keyWindow]
rootViewController].view;
CGRect originalFrame = [[UIScreen mainScreen] bounds];
CGRect adjustedFrame = [rootView convertRect:originalFrame fromView:nil];UIAlertView将自身插入作为keyWindow的RootViewController的看法。我有避免出现极端情况的逻辑，因为如果出现警报视图，则用户将无法与键盘进行交互，因此通常无需在那时抓住键盘框架。
我们也必须考虑设备的方向：
CGFloat screenHeight;
// it is important to do this after presentModalViewController:animated:
if ([[UIApplication sharedApplication] statusBarOrientation] == UIDeviceOrientationPortrait || [[UIApplication sharedApplication] statusBarOrientation] == UIDeviceOrientationPortraitUpsideDown){
screenHeight = [UIScreen mainScreen].applicationFrame.size.height;
}
else{
screenHeight = [UIScreen mainScreen].applicationFrame.size.width;
}NSLog(@"%.0f", [[UIScreen mainScreen] bounds].size.width);
NSLog(@"%.0f", [[UIScreen mainScreen] bounds].size.height);现代答案：
如果您的应用程序支持iPad上的拆分视图，则此问题会变得有些复杂。您需要窗口的大小，而不是屏幕的大小，它可能包含2个应用程序。运行时窗口的大小也可能会有所不同。
使用应用程序主窗口的大小：
UIApplication.shared.delegate?.window??.bounds.size ?? .zero注意：以上方法在启动时可能会在窗口变为关键窗口之前得到错误的值。如果只需要宽度，则强烈建议使用以下方法：
UIApplication.shared.statusBarFrame.width旧解决方案使用 UIScreen.main.bounds将返回设备的边界。如果您的应用程序以拆分视图模式运行，则其尺寸错误。
self.view.window 当应用包含2个或更多窗口且窗口尺寸较小时，最热的答案中的尺寸可能会错误。
利用这些Structs信息了解有关Swift 3.0中当前设备的有用信息
struct ScreenSize { // Answer to OP's question
static let SCREEN_WIDTH = UIScreen.main.bounds.size.width
static let SCREEN_HEIGHT = UIScreen.main.bounds.size.height
static let SCREEN_MAX_LENGTH = max(ScreenSize.SCREEN_WIDTH, ScreenSize.SCREEN_HEIGHT)
static let SCREEN_MIN_LENGTH = min(ScreenSize.SCREEN_WIDTH, ScreenSize.SCREEN_HEIGHT)
}
struct DeviceType { //Use this to check what is the device kind you're working with
static let IS_IPHONE_4_OR_LESS = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH < 568.0
static let IS_IPHONE_SE = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 568.0
static let IS_IPHONE_7 = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 667.0
static let IS_IPHONE_7PLUS = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 736.0
static let IS_IPHONE_X = UIDevice.current.userInterfaceIdiom == .phone && ScreenSize.SCREEN_MAX_LENGTH == 812.0
static let IS_IPAD = UIDevice.current.userInterfaceIdiom == .pad && ScreenSize.SCREEN_MAX_LENGTH == 1024.0
}
struct iOSVersion { //Get current device's iOS version
static let SYS_VERSION_FLOAT = (UIDevice.current.systemVersion as NSString).floatValue
static let iOS7 = (iOSVersion.SYS_VERSION_FLOAT >= 7.0 && iOSVersion.SYS_VERSION_FLOAT < 8.0)
static let iOS8 = (iOSVersion.SYS_VERSION_FLOAT >= 8.0 && iOSVersion.SYS_VERSION_FLOAT < 9.0)
static let iOS9 = (iOSVersion.SYS_VERSION_FLOAT >= 9.0 && iOSVersion.SYS_VERSION_FLOAT < 10.0)
static let iOS10 = (iOSVersion.SYS_VERSION_FLOAT >= 10.0 && iOSVersion.SYS_VERSION_FLOAT < 11.0)
static let iOS11 = (iOSVersion.SYS_VERSION_FLOAT >= 11.0 && iOSVersion.SYS_VERSION_FLOAT < 12.0)
static let iOS12 = (iOSVersion.SYS_VERSION_FLOAT >= 12.0 && iOSVersion.SYS_VERSION_FLOAT < 13.0)
}如果您希望屏幕宽度/高度与设备方向无关（适合调整从纵向方向启动的仅纵向视图控制器的大小）：
CGFloat screenWidthInPoints = [UIScreen mainScreen].nativeBounds.size.width/[UIScreen mainScreen].nativeScale;
CGFloat screenHeightInPoints = [UIScreen mainScreen].nativeBounds.size.height/[UIScreen mainScreen].nativeScale;[UIScreen mainScreen] .nativeBounds <-来自文档->物理屏幕的边界矩形，以像素为单位。该矩形基于设备的纵向放置。该值不会随着设备旋转而改变。
这是一种获取屏幕尺寸的快捷方法：
print(screenWidth)
print(screenHeight)
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
}这些作为标准功能包括在：
CGFloat width = [[UIScreen mainScreen] bounds].size.width;
CGFloat height = [[UIScreen mainScreen]bounds ].size.height;
您可以使用“ SCREEN_WIDTH”将这些宏放置在pch文件中，并在项目中的任何位置使用
#define SCREEN_WIDTH ((([UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortrait) || ([UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown)) ? [[UIScreen mainScreen] bounds].size.width : [[UIScreen mainScreen] bounds].size.height)和“ SCREEN_HEIGHT”
#define SCREEN_HEIGHT ((([UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortrait) || ([UIApplication sharedApplication].statusBarOrientation == UIInterfaceOrientationPortraitUpsideDown)) ? [[UIScreen mainScreen] bounds].size.height : [[UIScreen mainScreen] bounds].size.width)使用示例：
CGSize calCulateSizze ;
calCulateSizze.width = SCREEN_WIDTH/2-8;
calCulateSizze.height = SCREEN_WIDTH/2-8;