非常简单的解决方法

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
{
    CGSize result = [[UIScreen mainScreen] bounds].size;
    if(result.height == 480)
    {
        // iPhone Classic
    }
    if(result.height == 568)
    {
        // iPhone 5
    }
}

通过这种方式，您可以检测设备系列。

    #import <sys/utsname.h>
    NSString* deviceName()
    {
        struct utsname systemInformation;
        uname(&systemInformation);
        NSString *result = [NSString stringWithCString:systemInformation.machine
                                              encoding:NSUTF8StringEncoding];
        return result;
    }

    #define isIPhone5  [deviceName() rangeOfString:@"iPhone5,"].location != NSNotFound
    #define isIPhone5S [deviceName() rangeOfString:@"iPhone6,"].location != NSNotFound

在Swift, iOS 8+项目中，我喜欢在UIScreen上做一个扩展，比如:

extension UIScreen {

    var isPhone4: Bool {
        return self.nativeBounds.size.height == 960;
    }

    var isPhone5: Bool {
        return self.nativeBounds.size.height == 1136;
    }

    var isPhone6: Bool {
        return self.nativeBounds.size.height == 1334;
    }

    var isPhone6Plus: Bool {
        return self.nativeBounds.size.height == 2208;
    }

}

(注意:nativeBounds是以像素为单位)。

然后代码会是这样的:

if UIScreen.mainScreen().isPhone4 {
    // do smth on the smallest screen
}

因此，代码清楚地表明这是对主屏幕的检查，而不是对设备模型的检查。

我冒昧地将Macmade的宏放入一个C函数中，并正确地命名它，因为它可以检测宽屏可用性，而不一定是iPhone 5。

如果项目不包含Default-568h@2x.png，宏也不会检测到在iPhone 5上运行。如果没有新的默认图像，iPhone 5将显示常规的480x320屏幕大小(以点数计算)。因此，检查不仅仅是宽屏可用性，而是宽屏模式是否启用。

BOOL isWidescreenEnabled()
{
    return (BOOL)(fabs((double)[UIScreen mainScreen].bounds.size.height - 
                                               (double)568) < DBL_EPSILON);
}

如果项目是用Xcode 6创建的，那么使用下面提到的代码来检测设备。

printf("\nDetected Resolution : %d x %d\n\n",(int)[[UIScreen mainScreen] nativeBounds].size.width,(int)[[UIScreen mainScreen] nativeBounds].size.height);

if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){
    if ([[UIScreen mainScreen] respondsToSelector: @selector(scale)])
    {
        if([[UIScreen mainScreen] nativeBounds].size.height == 960 || [[UIScreen mainScreen] nativeBounds].size.height == 480){
            printf("Device Type : iPhone 4,4s ");

        }else if([[UIScreen mainScreen] nativeBounds].size.height == 1136){
            printf("Device Type : iPhone 5,5S/iPod 5 ");

        }else if([[UIScreen mainScreen] nativeBounds].size.height == 1334){
            printf("Device Type : iPhone 6 ");

        }else if([[UIScreen mainScreen] nativeBounds].size.height == 2208){
            printf("Device Type : iPhone 6+ ");

        }
    }
}else{
    printf("Device Type : iPad");
}

如果项目是在Xcode 5中创建并在Xcode 6中打开的，那么使用下面提到的代码来检测设备。(如果没有为iPhone 6,6+分配启动图像，此代码有效)

printf("\nDetected Resolution : %d x %d\n\n",(int)[[UIScreen mainScreen] nativeBounds].size.width,(int)[[UIScreen mainScreen] nativeBounds].size.height);
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){
    if ([[UIScreen mainScreen] respondsToSelector: @selector(scale)])
    {
       if([[UIScreen mainScreen] nativeBounds].size.height == 960 || [[UIScreen mainScreen] nativeBounds].size.height == 480){
            printf("Device Type : iPhone 4,4s");
            appType=1;
        }else if([[UIScreen mainScreen] nativeBounds].size.height == 1136 || [[UIScreen mainScreen] nativeBounds].size.height == 1704){
            printf("Device Type : iPhone 5,5S,6,6S/iPod 5 ");
            appType=3;
        }
    }
}else{
    printf("Device Type : iPad");
    appType=2;
}

如果你仍然在使用Xcode 5，那么使用下面的代码来检测设备(iPhone 6和6+将不会被检测到)

printf("\nDetected Resolution : %d x %d\n\n",(int)[[UIScreen mainScreen] bounds].size.width,(int)[[UIScreen mainScreen] bounds].size.height);
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){
    if ([[UIScreen mainScreen] respondsToSelector: @selector(scale)])
    {
        CGSize result = [[UIScreen mainScreen] bounds].size;
        CGFloat scale = [UIScreen mainScreen].scale;
        result = CGSizeMake(result.width * scale, result.height * scale);
        if(result.height == 960 || result.height == 480){
            printf("Device Type : iPhone 4,4S ");

        }else if(result.height == 1136){
            printf("Device Type : iPhone 5s/iPod 5");

        }
    }
}else{
    printf("Device Type : iPad");

}

Add a 'New Swift File'-> AppDelegateEx.swift add an extension to AppDelegate import UIKit extension AppDelegate { class func isIPhone5 () -> Bool{ return max(UIScreen.mainScreen().bounds.width, UIScreen.mainScreen().bounds.height) == 568.0 } class func isIPhone6 () -> Bool { return max(UIScreen.mainScreen().bounds.width, UIScreen.mainScreen().bounds.height) == 667.0 } class func isIPhone6Plus () -> Bool { return max(UIScreen.mainScreen().bounds.width, UIScreen.mainScreen().bounds.height) == 736.0 } } usage: if AppDelegate.isIPhone5() { collectionViewTopConstraint.constant = 2 }else if AppDelegate.isIPhone6() { collectionViewTopConstraint.constant = 20 }