在我的本机0.59.5 public HeaderNavButton = [
{
text: "main",
link: "/main",
id: "header-nav-button-main",
class: "btn btn-primary font-weight-bold",
},
{
text: "news",
link: "/news",
id: "header-nav-button-news",
class: "btn btn-primary font-weight-bold",
},
{
text: "entertainment",
link: "/entertainment",
id: "header-nav-button-entertainment",
class: "btn btn-primary font-weight-bold",
},
{
text: "sports",
link: "/sports",
id: "header-nav-button-sports",
class: "btn btn-primary font-weight-bold",
},
{
text: "business",
link: "/business",
id: "header-nav-button-business",
class: "btn btn-primary font-weight-bold",
},
{
text: "society",
link: "/society",
id: "header-nav-button-society",
class: "btn btn-primary font-weight-bold",
},
{
text: "wellness",
link: "/wellness",
id: "header-nav-button-wellness",
class: "btn btn-primary font-weight-bold",
},
{
text: "food",
link: "/food",
id: "header-nav-button-food",
class: "btn btn-primary font-weight-bold",
},
{
text: "travel",
link: "/travel",
id: "header-nav-button-travel",
class: "btn btn-primary font-weight-bold",
},
{
text: "autos",
link: "/autos",
id: "header-nav-button-autos",
class: "btn btn-primary font-weight-bold",
},
{
text: "media",
link: "/media",
id: "header-nav-button-media",
class: "btn btn-primary font-weight-bold",
},
中有一个异步方法检索jwt令牌。该方法更像是包装方法，并在App.js之后被调用：
App.js初始化后未定义jwt令牌：
....
async function getToken() {
try {
const result = await helper.getJwtToken();
console.log("secure store : ", result);
if (!result) this.props.navigation.navigate("Signup");
return result;
} catch(err) {
console.log("Error in retrieve jwt token : ", err.message);
return {};
};
};
//socket.io
const result = getToken();
let jwt = result.password;
console.log("jwt token in App.js : ", jwt);
const socket = io(GLOBAL.BASE_URL + `?token=${jwt}`, {
//const socket = io(GLOBAL.BASE_URL, {
transports: ['websocket'],
jsonp: false
});
console.log("socket id in App.js : ", socket.id);
但是在初始化后启动初始组件时，类似的代码（检索jwt令牌）可以正常工作，并且成功检索到存储的jwt令牌，socket.io也是如此。如何使此05-20 22:47:31.660 23027 23027 D ReactNative: ReactInstanceManager.ctor()
05-20 22:47:31.904 23027 23027 D ReactNative: ReactInstanceManager.createReactContextInBackground()
05-20 22:47:31.905 23027 23027 D ReactNative: ReactInstanceManager.recreateReactContextInBackgroundInner()
05-20 22:47:43.156 23027 23027 D ReactNative: ReactInstanceManager.onJSBundleLoadedFromServer()
05-20 22:47:43.206 23027 23027 D ReactNative: ReactInstanceManager.recreateReactContextInBackground()
05-20 22:47:43.207 23027 23027 D ReactNative: ReactInstanceManager.runCreateReactContextOnNewThread()
05-20 22:47:43.346 23027 23096 D ReactNative: ReactInstanceManager.createReactContext()
05-20 22:47:43.525 23027 23096 D ReactNative: Initializing React Xplat Bridge.
05-20 22:47:43.545 23027 23096 D ReactNative: Initializing React Xplat Bridge before initializeBridge
05-20 22:47:43.572 23027 23096 D ReactNative: Initializing React Xplat Bridge after initializeBridge
05-20 22:47:43.572 23027 23096 D ReactNative: CatalystInstanceImpl.runJSBundle()
05-20 22:47:43.575 23027 23101 D ReactNative: ReactInstanceManager.setupReactContext()
05-20 22:47:43.577 23027 23101 D ReactNative: CatalystInstanceImpl.initialize()
05-20 22:47:43.593 23027 23101 D ReactNative: ReactInstanceManager.attachRootViewToInstance()
05-20 22:47:49.001 23027 23100 I ReactNativeJS: 'secure store : ', ''
05-20 22:47:49.002 23027 23100 I ReactNativeJS: 'Error in retrieve jwt token : ', 'undefined is not an object (evaluating \'this.props.navigation\')'
05-20 22:47:49.049 23027 23100 I ReactNativeJS: 'socket id in App.js : ', undefined
代码在async getToken中工作以进行初始化？
答案 0 :(得分：1)
问题在于您不必等待getToken()函数完成。
在调用getToken()时尝试使用 await ，如下所示：
//socket.io
const result = await getToken();
let jwt = result.password;
console.log("jwt token in App.js : ", jwt);
const socket = io(GLOBAL.BASE_URL + `?token=${jwt}`, {
//const socket = io(GLOBAL.BASE_URL, {
transports: ['websocket'],
jsonp: false
});
console.log("socket id in App.js : ", socket.id);