转:http://blog.csdn.net/totogogo/article/details/7355203
有几种方法
some developers recommend use singleton patter (ref link http://blog.csdn.net/kmyhy/article/details/7026511)
方法1:使用静态变量 (不推荐)
方法2: 使用singleton pattern (ref link: http://nice.iteye.com/blog/855839)
方法3:把全局变量设置到AppDelegate中
例: 定义和使用一个全局变量"isLogin"
AppDelegate.h
@interface AppDelegate :UIResponder <UIApplicationDelegate>
@property (strong,nonatomic)UIWindow *window;
@propertyBOOL isLogin;
@end
AppDelegate.m
@implementation AppDelegate
@synthesize window =_window;
@synthesize isLogin;
@end
AppDelegate *delegate=(AppDelegate*)[[UIApplicationsharedApplication]delegate];
delegate.isLogin=YES;