我正在使用react-native-navigation,我无法为Android设置正确的按钮(应用字体和颜色等)(并且看到黑色的大写文本) . 但是这些样式适用于ios . 任何人都能提出一些解决方案吗

static navigatorStyle = {
    navBarHidden: false,
   navBarRightButtonFontSize: 15,
   navBarRightButtonFontFamily: 'OpenSans',
   topBarElevationShadowEnabled: false,
   topBarShadowColor: '#fff',
   topBarShadowOpacity: 0,
   navBarNoBorder: true,
   navBarBackgroundColor: '#fff',
   screenBackgroundColor: '#fff',
   navBarButtonColor: '#333',
   tabBarHidden: true,
    orientation: 'portrait,
    tabBarHidden: false,
    navBarRightButtonColor: '#F47F28',
}

static navigatorButtons = {
        leftButtons: [{
            icon: images.close,
            buttonColor: '#333333',
            disableIconTint: true,
            id: 'back'
        }],
        rightButtons: [{
            title: 'Sign out',
            buttonColor: '#F47F28',
            disableIconTint: true,
            id: 'signout'
        }]
    }