使用FileReader将文件转换为base64格式时出现Uncaught TypeError错误

Question

我想使用FileReader将文件转换为base64格式。但是我收到了Uncaught TypeError错误。如何防止这种情况发生，如何将文件成功转换为base64格式？

logs

控制台日志

[File]
0: File {_relativePath: "", name: "5-Defect-Management-Logs.docx", lastModified: 1576500873045, lastModifiedDate: Mon Dec 16 2019 15:54:33 GMT+0300 (GMT+03:00), webkitRelativePath: "", …}
length: 1
__proto__: Array(0)


PPP14.js:152 Uncaught TypeError: Failed to execute 'readAsDataURL' on 'FileReader': parameter 1 is not of type 'Blob'.
    at onupdatefiles (PPP14.js:152)
    at options.onupdatefiles (react-filepond.js:80)
    at exposeEvent (filepond.js:11728)
    at filepond.js:11744

反应js

                        <div className="App">
                            <FilePond
                                onupdatefiles={(fileItems) => {
                                    props.values.addendumA = fileItems.map(fileItem => fileItem.file)
                                    console.log('addendumA instance has initialised',props.values.addendumA)

                                    if(props.values.addendumA){
                                        var reader = new FileReader();
                                        reader.readAsDataURL(props.values.addendumA);
                                    }

                                    }
                                }
                            />

                        </div>