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Android入门之分辨率和密度

Android Resolution Vs Pixel Density in Displays

基础概念 (Terms and concepts) Screen size(屏幕尺寸) 按屏幕对角测量的实际物理尺寸(Actual physical size, measured as the screen’s diagonal). Screen density(屏幕密度) 屏幕物理区域中的像素量(the quantity of pixels)；通常称为 dpi（每英寸点数）dpi ...

Posted by Vivi CAO on January 5, 2017

Android adb调试命令集合

Android adb command debug usages

一些实用的命令发送广播关闭USB $ adb shell am broadcast -a android.hardware.usb.action.USB_STATE --ez connected "false" 关闭gyroscope(陀螺仪) 硬件相关，可能有变动 $ adb shell echo 0 > /sys/class/sensors/bmg160/...

Posted by Vivi CAO on October 9, 2016

Android Touch System

Mastering the Android Touch System

Mastering the Android Touch system 1. How Android Deal With Touch? So every event that comes from the touch screen on the device into your application is wrapped up in one of these MotinEvents. T...

Posted by Vivi CAO on August 27, 2016

Java零星知识点汇集

Java Brief Sum-up

1. 基本类型(Primitive type)中float和double的区别原文摘自 stackoverflow: http://stackoverflow.com/a/2386882/4710864，内容如下: Huge difference. As the name implies, a double has 2x the precision of float[1]. ...

Posted by Vivi Cao on August 15, 2016

Android性能分析工具之 —— vmstat

vmstat —— Android measurement

vmstat使用 vmstat: virtual Memory Statistics (虚拟内存统计), 是一个很有价值的监控工具，可以实时提供memory、block IO和CPU状态信息。它用来对系统整体的情况进行统计，通过它可以快速了解当前系统运行情况及可能碰到的问题。 Android中vmstat的提取命令如下： Example: vmstat 1 3 ...

Posted by Vivi Cao on August 14, 2016

Android N background optimization

Google I/O 2016

1 Battery Optimizations 1.1 Introduction Where does the power on our mobile phones go? Turns out, when the screen is on, it dominates the power consumption on your phone more than anything else....

Posted by Vivi Cao on August 12, 2016

Bash Shell: Change Shell Prompt

How to change Shell Prompt under Linux or UNIX

What’s Shell Prompt Once you open kind of Terminal on Linux, you should see the Unix command prompt, also known as the "shell prompt", appearing at the left side of your screen. This prompt means ...

Posted by Vivi CAO on July 26, 2016

How to analysis Alarm dumpsys & log

Android AlarmManager Actual Analysis

本文系本作者原创，如有任何知识产权、版权问题或理论错误，还请指正。转载请注明原作者及出处，谢谢配合。序言这一篇基于前一篇“Android AlarmManager Workflow”的基础上继续深入解释如何分析AlarmManagerService的问题，主要从android log，dumpsys info和一些知识点的记录着手，力求全面分析该类的知识点。 andro...

Posted by Vivi CAO on July 22, 2016

Android Alarm Manager Workflow

Describe the detail implement of the AlarmManagerService

本文系本作者原创，如有任何知识产权、版权问题或理论错误，还请指正。转载请注明原作者及出处，谢谢配合。 Alarm Introduce Alarm是基于AlarmManager类的闹钟机制，它可以使应用在其生命周期之外执行基于特定时间的操作。比如，定时让service在后台下载天气预报。而该种操作如果发生在应用生命周期内应该尽量避免使用Alarm而是用Handler类配合Tim...

Posted by Vivi Cao on July 12, 2016

How to analysis Android Performance

Android Performance Topic

本文系本作者原创，如有任何知识产权、版权问题或理论错误，还请指正。转载请注明原作者及出处，谢谢配合。如何分析Android performance问题? 检查CPU问题 — “手机是否发热” 看是否因为高温而降频 CPU信息：一般情况“2-7” 6核， CPU0, CPU1一般不开, CPU2-CPU3（大核），CPU4，CPU5，CPU6...

Posted by Vivi CAO on June 23, 2016

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