Ionic V4 用 HttpClient 上傳圖片

openCamera() {
    const options: CameraOptions = {
        quality: 50,
        destinationType: this.camera.DestinationType.FILE_URI,
        encodingType: this.camera.EncodingType.JPEG,
        mediaType: this.camera.MediaType.PICTURE
    };
    this.camera.getPicture(options).then((fileUri) => {
        this.uploadPhoto(fileUri);
    }).catch(cameraError => {
        console.log(cameraError);
    });
}

private readFile(file: any) {
    const reader = new FileReader();
    reader.onloadend = () => {
        const formData = new FormData();
        const imgBlob = new Blob([reader.result], {type: file.type});
        formData.append('type', 'avatar');
        formData.append('file', imgBlob, file.name);
        this.postData(formData);
    };
    reader.readAsArrayBuffer(file);
}


private postData(formData) {
    const httpOptions = {
        headers: new HttpHeaders({
            ContentTypeSkip:  'Content-Type-Skip',
        })
    };

    this.http.post(environment.API_URL + 'members/avatar', formData, httpOptions)
    .subscribe(response => {
        console.log(response);
    }, avatarError => {
        console.log(avatarError);
    });
}

if (!request.headers.has('ContentTypeSkip')) {
    if (!request.headers.has('Content-Type')) {
        request = request.clone({headers: request.headers.set('Content-Type', 'application/json')});
    }
}