swift -- 适配准备

//公共全局变量
public var DEVICE_TYPE:Int=0 //0为iPhone4s及以下 1为iPhone5s及以下 2为iPhone6 3为iPhone6p及以上
public var DEVICE_WIDTH:CGFloat=0 //设备宽度
public var DEVICE_HIGHT:CGFloat=0 //设备高度
public var FIT_RATE:CGFloat=1 //适配比率

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
let screenRect:CGRect=UIScreen.mainScreen().bounds
//初始化设备信息
initDeviceInfo(screenRect)

return true
}

func initDeviceInfo(deviceRect:CGRect){

DEVICE_WIDTH=deviceRect.width
DEVICE_HIGHT=deviceRect.height

//4s 宽320.0 高480.0
//5s 宽320.0 高568.0
//6  宽375.0 高667.0
//6p 宽414.0 高736.0

if DEVICE_HIGHT>=736{
//iPhone6p
DEVICE_TYPE=3
FIT_RATE=1.2
}else if DEVICE_HIGHT>=667 && DEVICE_HIGHT<736{
//iPhone6
DEVICE_TYPE=2
FIT_RATE=1
}else if DEVICE_HIGHT>=568 && DEVICE_HIGHT<667{
//iPhone5s
DEVICE_TYPE=1
FIT_RATE=1
}else{
//iPhone4s
DEVICE_TYPE=0
FIT_RATE=0.8
}

}

class func getCurrentDeviceDpi()->CGFloat{
if DEVICE_TYPE==0{
return 3.78
}else if DEVICE_TYPE==1{
return 3.78
}else if DEVICE_TYPE==2{
return 3.17
}else if DEVICE_TYPE==3{
return 2.78
}else{
return 1.31
}
}