// 用到的开源项目 ① Picasso A powerful image downloading and caching library for Android http://square.github.io/picasso/ ② Otto An enhanced event bus with emphasis on Android support http://square.github.io/otto/ ③ZXing ZXing is an open-source, multi-format 1D/2D barcode image processing library implemented in Java, with ports to other languages. https://github.com/zxing/zxing