控制Default.png图片的显示时间

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions   
//等待1秒进入首页
  self.timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired:) userInfo:nil repeats:NO];
[[NSRunLoop currentRunLoop] addTimer:self.connectionTimer forMode:NSDefaultRunLoopMode];
 do{
    [[NSRunLoop currentRunLoop]runUntilDate:[NSDate dateWithTimeIntervalSinceNow:1.0]];
//控制default图片显示的时间
 }while (!done);    
-(void)timerFired:(NSTimer *)timer{
    done=YES;
}