prefix.pch文件的一些简单使用

//定义NSString常量
#define     ServiceName     @"cn.zmfc"
//定义颜色
#define BackgroudColor  [UIColor colorWithRed:232/255.0 green:235/255.0 blue:240/255.0 alpha:1.0]
//定义IOS系统版本等
#define   currentVersion        [[UIDevice currentDevice].systemVersion floatValue]
#define   isIOS8        (currentVersion >= 8.0)
#define   isIOS7        (!isIOS8 && currentVersion >= 7.0)
#define   isIOS6        (currentVersion <= 6.0)
//定义数组
#define  ScatterArray   @[@"mega",@"medium",@"small",@"person",@"other"];

if(isIOS8){
    //要做的事
}