AsyncStorage not resolving or rejecting

问题

I'm trying to get an item from async storage.

componentDidMount() {
    console.log('componentDidMount')
    AsyncStorage.getItem(STORAGE_KEY)
      .then(storage => console.log('then', storage))
      .catch(err => console.log('catch', err))
}

Also trying this way:

componentDidMount() {
    console.log('componentDidMount')
    AsyncStorage.getItem(STORAGE_KEY, (err, data) => {
      console.log('data', data);
      console.log('err', err)
    });
 }

But no matter how I do it, the debugger is outputting only the componentDidMount log and I'm not getting results at all.

Any idea what's wrong here?

EDIT: I'm running the app through expo

回答1:

There was a problem with expo. After restarting expo completely the same code I originally posted worked fine.

回答2:

You should try this:

async componentDidMount(){  
  await AsyncStorage.getItem(STORAGE_KEY)  
    .then( (value) =>{  
       console.warn(value);  
    }  
 );  
}

Hope it works.

回答3:

I had that problem with android, and I could only solve it bundling.

react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res.

I added this command in the scripts in package.json.

回答4:

AsyncStorage is an asynchronous function. It means that id you 'd like to use it in a function, it have to be asynchronous. The way to make it asynchronous is putting async keyword before the name of the function.

async componentDidMount() {
    console.log('componentDidMount')
    AsyncStorage.getItem(STORAGE_KEY)
      .then(storage => console.log('then', storage))
      .catch(err => console.log('catch', err))
}

This is how it should be. Greetings

来源：https://stackoverflow.com/questions/48251830/asyncstorage-not-resolving-or-rejecting

标签

react-native

asyncstorage