无法在'FileReader'上执行'readAsText'：参数1不是'Blob'类型

Question

I got the errors failed to execute 'readAsText' on 'FileReader': parameter 1 is not of type' Blob'.My library is 0.10.8 version. I have tried to downgrade react native fetch blob to 0.9.5 but i got another error.

listeners is not defined

i have read problem at github, but i don't really understand with their solutions i confused right now.

const Blob = RNFetchBlob.polyfill.Blob

const fs = RNFetchBlob.fs

window.XMLHttpRequest = RNFetchBlob.polyfill.XMLHttpRequest

window.Blob = Blob

​

const screenWidth = Dimensions.get('window').width

​

const uploadImage = (uri, imageName, mime = 'image/jpg') => {

return new Promise((resolve, reject) => {

const uploadUri = Platform.OS === 'ios' ? uri.replace('file://', '') : uri

let uploadBlob = null

const imageRef = firebaseApp.storage().ref('posts').child(imageName)

fs.readFile(uploadUri, 'base64')

.then((data) => {

return Blob.build(data, { type: `${mime};BASE64` })

})

.then((blob) => {

uploadBlob = blob

return imageRef.put(blob, { contentType: mime })

})

.then(() => {

uploadBlob.close()

return imageRef.getDownloadURL()

})

.then((url) => {

resolve(url)

})

.catch((error) => {

reject(error)

})

})

}

Answer 1

I solved it by resetting the window.XMLHttpRequest to it's original state after finished using the fetch blob for uploading my image to cloud. Hope it helps :)

 const Blob = FetchBlob.polyfill.Blob; // Keep an original copy of window.XMLHttpRequest before set it to FetchBlob.polyfill.XMLHttpRequest const oriWindowXMLHttpRequest = window.XMLHttpRequest; window.XMLHttpRequest = FetchBlob.polyfill.XMLHttpRequest; window.Blob = Blob; return new Promise((resolve, reject) => { Blob.build(imageFile, { type: mime }) .then(blob => { uploadBlob = blob; return imageRef.put(blob, { contentType: mime }); }) .then(() => { uploadBlob.close(); return imageRef.getDownloadURL(); }) .then(url => { // Reset it to the original WindowXMLHttpRequest after the task has been done completely window.XMLHttpRequest = oriWindowXMLHttpRequest; resolve(getSuccessResponse(url)); }) .catch(error => { // Reset it to the original WindowXMLHttpRequest after the task has been done completely window.XMLHttpRequest = oriWindowXMLHttpRequest; showToast(getErrorMessage(error)); reject(getFailResponse(error)); }); });