status bar样式设置

可以设置的地方有两个：plist设置里面 和 程序代码里

一.View controller-based status bar appearance设置为YES，则[UIApplication sharedApplication].statusBarStyle 无效。可以使用下面3个方法修改

- (UIStatusBarStyle)preferredStatusBarStyle;

- (UIViewController *)childViewControllerForStatusBarStyle;

- (void)setNeedsStatusBarAppearanceUpdate

1. 在vc中重写preferredStatusBarStyle方法。

-(UIStatusBarStyle)preferredStatusBarStyle

{

return UIStatusBarStyleDefault;

}

2.在viewDidload中调用：[self setNeedsStatusBarAppearanceUpdate];

在NavigationController里上面的方法没有用，只会调用navigation controller中的preferredStatusBarStyle方法
可通过自定义一个nav类。重写他的preferredStatusBarStyle方法

- (UIStatusBarStyle)preferredStatusBarStyle {
    return self.topViewController.preferredStatusBarStyle;
}

二.在info.plist中，View controller-based status bar appearance 设为 NO,这时application的设置优先级最高，

状态栏字体颜色由下面属性设置

[UIApplication sharedApplication].statusBarStyle

*iOS9以后api说明

// Setting the statusBarStyle does nothing if your application is using the default UIViewController-based status bar system.

@property(readwrite, nonatomic) UIStatusBarStyle statusBarStyle NS_DEPRECATED_IOS(2_0, 9_0, "Use -[UIViewController preferredStatusBarStyle]");

- (void)setStatusBarStyle:(UIStatusBarStyle)statusBarStyle animated:(BOOL)animated NS_DEPRECATED_IOS(2_0, 9_0, "Use -[UIViewController preferredStatusBarStyle]");