iOS SDK是否提供了一种简单的方法来检查currentDevice是否具有高分辨率的显示器(retina) ?
我现在发现的最好的方法是:
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] == YES && [[UIScreen mainScreen] scale] == 2.00) {
// RETINA DISPLAY
}
iOS SDK是否提供了一种简单的方法来检查currentDevice是否具有高分辨率的显示器(retina) ?
我现在发现的最好的方法是:
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] == YES && [[UIScreen mainScreen] scale] == 2.00) {
// RETINA DISPLAY
}
当前回答
这是一个方便的快速扩展:
Swift v5更新:
extension UIScreen {
public var isRetina: Bool {
guard let scale = screenScale else {
return false
}
return scale >= 2.0
}
public var isRetinaHD: Bool {
guard let scale = screenScale else {
return false
}
return scale >= 3.0
}
private var screenScale: CGFloat? {
guard UIScreen.main.responds(to: #selector(getter: scale)) else {
return nil
}
return UIScreen.main.scale
}
}
用法:
if UIScreen.main.isRetina {
// Your code
}
原:
extension UIScreen {
public func isRetina() -> Bool {
return screenScale() >= 2.0
}
public func isRetinaHD() -> Bool {
return screenScale() >= 3.0
}
private func screenScale() -> CGFloat? {
if UIScreen.mainScreen().respondsToSelector(Selector("scale")) {
return UIScreen.mainScreen().scale
}
return nil
}
}
用法:
if UIScreen.mainScreen().isRetina() {
// your code
}
其他回答
只是为了结合@sickp的答案和下面来自@n13的评论,我把它做成了一个UIScreen类别,这似乎工作得很好。检查在您第一次调用它时完成,然后为以后的调用保存。
@interface UIScreen (RetinaCheck)
+ (BOOL)retinaScreen;
@end
static BOOL isRetinaScreen = NO;
static BOOL didRetinaCheck = NO;
@implementation UIScreen (RetinaCheck)
+ (BOOL)retinaScreen
{
if (!didRetinaCheck) {
isRetinaScreen = ([[self mainScreen] respondsToSelector:@selector(displayLinkWithTarget:selector:)] &&
([self mainScreen].scale == 2.0));
didRetinaCheck = YES;
}
return isRetinaScreen;
}
@end
可能对某人有用。
primulaveris's的修改版本,以简化最常见的用例。我用的是swift 2.2,但这应该没有关系。
extension UIScreen {
static var isRetina: Bool {
return screenScale >= 2.0
}
static var isRetinaHD: Bool {
return screenScale >= 3.0
}
static var screenScale:CGFloat {
return UIScreen.mainScreen().scale
}
}
然后像这样简单地使用它们
print(UIScreen.isRetina)
print(UIScreen.isRetinaHD)
print(UIScreen.screenScale)
+(BOOL)iPhoneRetina{
return ([[UIScreen mainScreen] respondsToSelector:@selector(displayLinkWithTarget:selector:)] && ([UIScreen mainScreen].scale == 2.0))?1:0;
}
这是一个方便的快速扩展:
Swift v5更新:
extension UIScreen {
public var isRetina: Bool {
guard let scale = screenScale else {
return false
}
return scale >= 2.0
}
public var isRetinaHD: Bool {
guard let scale = screenScale else {
return false
}
return scale >= 3.0
}
private var screenScale: CGFloat? {
guard UIScreen.main.responds(to: #selector(getter: scale)) else {
return nil
}
return UIScreen.main.scale
}
}
用法:
if UIScreen.main.isRetina {
// Your code
}
原:
extension UIScreen {
public func isRetina() -> Bool {
return screenScale() >= 2.0
}
public func isRetinaHD() -> Bool {
return screenScale() >= 3.0
}
private func screenScale() -> CGFloat? {
if UIScreen.mainScreen().respondsToSelector(Selector("scale")) {
return UIScreen.mainScreen().scale
}
return nil
}
}
用法:
if UIScreen.mainScreen().isRetina() {
// your code
}
以上答案的Swift版本,>= 2.0规模,因此它包括iPhone 6+和其他未来的高于retina规模的设备:
if UIScreen.mainScreen().respondsToSelector(Selector("scale")) && UIScreen.mainScreen().scale >= 2.0 {
// code executed only on Retina device
}