自定义Status Bar的基本方法

方法一：利用私有API添加新图标
直接上代码：在具体视图控制器中重写addStatusBarImageNamed:removeOnExit:方法

- (void) addStatusBarImageNamed:(NSString*)image removeOnExit: (BOOL) remove {
if(_statusbarimage!=nil && _responds) {
if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"statusBarEnabled"] integerValue] == 1)
[self removeStatusBarImageNamed:_statusbarimage];
statusbarimage=image;
}
if (_responds) {
if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"statusBarEnabled"] integerValue] == 1)
[super addStatusBarImageNamed:image removeOnExit: remove];
}
}

 方法二：用新的UIWindow覆盖原来的状态栏
装载自：http://b.imi.im/?p=374
首先继承UIWindow，及init的方法，关键语句self.windowLevel = UIWindowLevelAlert;

- (id)init
{
    CGRect f = [[UIScreen mainScreen] bounds]; //获取屏幕区
    CGRect s = [[UIApplication sharedApplication] statusBarFrame]; //获取状态栏框架区
    self = [super initWithFrame:CGRectMake(0,0,f.size.width, s.size.height)];
    if(self != nil) {
        self.windowLevel = UIWindowLevelAlert;
        self.backgroundColor = [UIColor clearColor];

         [self makeKeyAndVisible];
    }
    return self;
}