statusBar显示白色字体
设置状态栏显示颜色为白色.
a. 在info.plist中,添加一项,选择View controller-based status bar appearance(箭头下拉中最后一项),设置为no;
b.在viewController或者自定义NavController中,设置 [UIApplicationsharedApplication].statusBarStyle = UIStatusBarStyleLightContent;
设置状态栏显示颜色为白色.