(1)创建View.xib文件
(2)AppDelegate.m
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
//设置背景颜色
self.window.backgroundColor = [UIColor greenColor];
[self.window makeKeyAndVisible];
//程序包
NSBundle *bundle = [NSBundle mainBundle];
//加载XIB,数组中一个元素
NSArray *arrary = [bundle loadNibNamed:@"View" owner:self options:nil];
UIView *view = [arrary lastObject];
// UIView *view = [[bundle loadNibNamed:@"View" owner:self options:nil] lastObject];
//将view现实在window上面
[self.window addSubview:view];
// [view release];