世博文件上传未按预期工作

Question

I'm searching for a document uploader for my app and I got the expo document uploader. But unfortunately when I'm going to test the app and nothings happens. Kindly let me know the solution for this.

https://snack.expo.io/S1HtdYQ1M

Answer 1

Your imports were outdated, importing ImagePicker from expo looks like this:

import * as ImagePicker from 'expo-image-picker';

Additionally, you were not requesting permissions. You should do so like this:

  componentDidMount() {
    this.getPermissionAsync();
  }

  getPermissionAsync = async () => {
    if (Constants.platform.ios) {
      const { status } = await Permissions.askAsync(Permissions.CAMERA_ROLL);
      if (status !== 'granted') {
        alert('Sorry, we need camera roll permissions to make this work!');
      }
    }
  };

Finally, if an async function seems to be doing nothing try wrapping it in a try/catch block so that you can see why it is failing as a failed promise does not always log correctly. Like this:

  _pickImage = async () => {
    try {
      let result = await ImagePicker.launchImageLibraryAsync({
        allowsEditing: true,
        aspect: [4, 3],
      });

      if (!result.cancelled) {
        this.setState({ image: result.uri });
      }
    } catch (e) {
      console.log(e);
    }
  };

Most importantly, you should always consult the documentation when approaching an issue like this. Expo's image picker documentation not only describes the above but gives you a working example.

Here is a modified, working version of your snack