David Dong

David Dong



  • posts

  • Fingerprint implementation in android 8.0 and later

    Since Android 8.0, Android has fully introduced the HIDL layer into the framework. The purpose is to separate vendor partition from system partition so that Android is capable to upgrade the framework through OTA without recompiling HAL. Correspondingly, the framework of fingerprint has also been reconstructed. This page will give an introduction about the difference in the fingerprint framework between android 7.0 (and early version) and android 8.0 (and later version).

  • Android Fingerprint Framework (3)

    Following the last two articles, this article will discuss the remaining part of the fingerprint framework on android. This article will end this topic.

  • Android Fingerprint Framework (2)

    This page will follow the last article to continue introducing the android fingerprint framework knowledge. The content is focused on android source code inspecting and analysis.

  • Android Fingerprint Framework (1)

    This page is trying to present a brief introduction on the android fingerprint framework, aimed at helping anyone who wants to learn android fingerprint-related knowledge, created by referring to some documents and android source code.

  • Fingerprint enrollment in Android

    When we do fingerprint enrollment in an android device, it will generate a fingerprint template that contains the user’s fingerprint information in a specified directory (for example, /data/vendor_de/0/fpdata/user.db), which depends on the system configuration.

  • Some tips for android development errors

    Today I met an error when I was trying to customize the android.widget.Button Class.😕
    The error information is

    "This custom view should extend android.support.v7.widget.AppCompatButton instead."
  • Python re module

    re module is a unique string matching module of Python.

  • Python struct.pack()

    Python uses struct.pack() to pack python data type into binary data (Byte Stream), which means convert a value to a string based on the format.

  • A quick way to hide app icon on andorid desktop

    Here introduces a quick way to hide the android app icon on the desktop. Although it isn’t a common case on the development or usage of android app, it deserves pay a little bit time reading for anyone who want to realize it.

  • Python 开发编码规范(转)

    这篇文档所给出的编码约定适用于在主要的Python发布版本中组成标准库的Python 代码,请查阅相关的关于在Python的C实现中C代码风格指南的描述。

  • Display mathematics formula in blog with MathJax

    When writing posts, I need to display mathematics formulas sometimes. I write posts with Markdown, I don’t want to save the formula into an image and load the image in markdown. It is better to write the Latex formula in the markdown file directly. MathJax helped me. This article will introduce what MathJax is and how to use MathJax.

  • Python Pillow library usage

    I recently completed some image processing works by Pillow Library. Pillow provides a powerful function and has friendly APIs to the developer. I thought it is necessary to make some notes here for the usage.