$ ionic cordova plugin add cordova-plugin-telerik-imagepicker
$ npm install @ionic-native/image-picker

$ ionic cordova plugin add cordova-plugin-file-transfer
$ npm install @ionic-native/file-transfer

import { ImagePicker } from '@ionic-native/image-picker/ngx';
import { FileTransfer} from '@ionic-native/file-transfer/ngx';

export class UploadPage {
  constructor(
    private imagePicker: ImagePicker,
    private transfer: FileTransfer
  ) {
  }
  // 选择图片，选择完成立即上传
  chooseImage() {
    const options = {
      maximumImagesCount: 1
      // width: int,
      // height: int,
      // quality: int (0-100),
      // outputType: int
    };
    this.imagePicker.getPictures(options).then((results) => {
      for (const res of results) {
        this.upload(res);
      }
    }, (err) => {
    });
  }
  // 上传文件
  upload(file) {
    const fileTransfer: FileTransferObject = this.transfer.create();
    const options: FileUploadOptions = {
      fileKey: 'file',
      fileName: timestamp() + '.jpg',
      params: {
        type: 'file',
        action: 'upload',
        timestamp: timestamp(),
        auth_token: '79e1bd1504962034c068461d58b9cd89a1d8a4a1'
      },
      headers: {}
    };
    fileTransfer.upload(file, 'https://imgbb.com', options)
      .then((data) => {
        alert('success');
      })
      .catch((e) => {
      });
  }
}