在 React Native 中将图像转换为 Base64

Question

我已经使用了react-native-image-picker，现在我从照片库中选择图像。要将图像发送到 API，我必须首先将其转换为 Base64，然后转换为字节数组。我的文件路径位于response.uri 中。我该怎么做？

当我执行 console.log(response) 时，我得到了这个结果

'Response = ', {
  fileSize: 6581432,
  longitude: -17.548928333333333,
  uri: 'file:///Users/shubhamb/Library/Developer/CoreSimulator/Devices/B58314DF-F0A9-48D2-B68A-984A02271B72/data/Containers/Data/Application/63143214-8A03-4AC8-A79C-42EC9B82E841/tmp/2AACBC57-0C07-4C98-985E-154668E6A384.jpg',
  fileName: 'IMG_0003.JPG',
  latitude: 65.682895,
  origURL: 'assets-library://asset/asset.JPG?id=9F983DBA-EC35-42B8-8773-B597CF782EDD&ext=JPG',
  type: 'image/jpeg',
  height: 2002,
  width: 3000,
  timestamp: '2012-08-08T18:52:11Z',
  isVertical: false,
}

Answer 1

由于您使用的是react-native-image-picker，它已经在其响应中返回了Base64值

ImagePicker.showImagePicker(options, (response) => {
  const base64Value = response.data;
});

响应的文档

Answer 2

我在更新应用程序时突然遇到了这个问题。我发现以前react-native-image-picker用来提供base64作为response.data。但现在选项对象中有一个includeBase64，以便您可以控制是否需要 Base64 数据。所以我的代码变成了如下所示

captureTradeLicenseImage() {
    let options = {
        maxHeight: 250,
        maxWidth: 350,
        includeBase64: true //add this in the option to include base64 value in the response
    }
    ImagePicker.launchCamera(options, (response)  => {
        console.log('Response = ', response)
        if (response.didCancel) {
            console.log('User cancelled image picker')
        }
        else if (response.error) {
            console.log('ImagePicker Error: ', response.error)
        }
        else if (response.customButton) {
            console.log('User tapped custom button: ', response.customButton)
        }
        else if (response.fileSize > 5242880) {
            Alert.alert(
                "Nilamhut Say\'s",
                "Oops! the photos are too big. Max photo size is 4MB per photo. Please reduce the resolution or file size and retry",
                [
                    { text: "OK", onPress: () => console.log('ok Pressed') }
                ],
                { cancelable: false }
            )
        }
        else {
            this.setState({tradeLicenseImageData: response.base64}) //access like this
        }
    })
}