iPhone遮盖系统栏，实现自定义效果的状态栏

CGRect frame = CGRectMake(0, 0, 320, 20);

UIWindow* wd = [[UIWindow alloc] initWithFrame:frame];

[wd setBackgroundColor:[UIColor clearColor]];

[wd setWindowLevel:UIWindowLevelAlert];

frame = CGRectMake(100, 0, 30, 20);

UIImageView* img = [[UIImageView alloc] initWithFrame:frame];

[img setImage:[UIImage imageNamed:@"00_0103.png"]];

[wd addSubview:img];

[wd makeKeyAndVisible];

[UIView beginAnimations:nil context:nil];

[UIView setAnimationDuration:2];

frame.origin.x += 150;

[img setFrame:frame];

[UIView commitAnimations];
上面的代码演示了创建一个小图标从时间的左侧移动到时间右侧的简单效果，喜欢的可以自己实现一些其他的效果