自定义状态栏

让状态栏上的文字变为变色，先在supporting files 里的plist文件中加一个ViewController－based status bar appearance 设为NO;

    UIView * view1 = [[UIView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 20)];

    view1.backgroundColor = [UIColor redColor];

    [self.view addSubview:view1];

    [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent];