javascript - React-native - 基于用户位置的drawerLabel

Question

我有一个 react-native 应用程序，我需要根据用户位置呈现一个菜单项，但是返回用户位置的函数是一个异步函数，我得到一个未定义的，所以我的问题是如何我根据用户位置设置 navigationOptions 的 drawerLabel 值？

static navigationOptions = () => ({
    drawerLabel: () => (OptionsDrawer.isOptionsItemAvaliable() ? 'Options' : null)
})




private static isOptionsItemAvaliable() {
    navigator.geolocation.getCurrentPosition((result) => this.setUserLocation(result.coords), ()=> {console.log("Failed to load user location")};
    return verifyUserLocation(userLocation);
}

private static setUserLocation(coordinates){
    userLocation = coordinates; //userLocation is a global variable
}

private static verifyUserLocation(coordinates){
//Code to check the user location and returns if it's inside the allowed area
}

Answer 1

尝试用自定义组件替换标题。在组件中，您可以将位置保持为状态，当位置更改时您会更新该状态。像这样:

class HomeScreen extends React.Component {
  static navigationOptions = {
    headerTitle: <LogoTitle />,
  };
}

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