修改ios7状态栏字体颜色

 [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent];

View controller-based status bar appearance   配置info.plist中

-(void)viewWillAppear:(BOOL)animated{

    [super viewWillAppear:animated];

//    [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleLightContent;

}

-(void)viewWillDisappear:(BOOL)animated{

    [super viewWillDisappear:animated];

//    [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleDefault;

}