Welcome to my Blog! Author:林建有

• Android TargetSDK28 升级SDK版本后适配修改点

  2019-07-03

  Android  TargetSDK28

  Android  TargetSDK28
  • Upgrade to TagertSDK 28
    • 前台服务需要添加 ForgroundService权限 否则系统会引发 SecurityException。
    • 非SDK API的限制

  Upgrade to TagertSDK 28

  前台服务需要添加 ForgroundService权限 否则系统会引发 SecurityException。

    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />	
  

  打开前台服务，需要有通知栏体现：

    Intent intent = new Intent(this, ForegroundService.class);
    ContextCompat.startForegroundService(this, intent);
  

  要请求让服务运行于前台，在ForegroundService.class里需要调用如下方法启动通知栏:

    startForeground(NOTIFICATION_ID, notification);
  

  非SDK API的限制

  对非Android SDK API的调用做了限制，通常会出现类似NoSuchClassException或NoSuchFieldException异常。

  非SDK API包括Android未公开的底层内部实现细节的API反射调用。还有NDK里未公开的方法调用等。

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• Android Storage Access Framework(SAF)

  2018-11-26

  Android  SAF

  Android  SAF
  • SAF存储访问框架介绍
  • 针对SD Card文件访问读写受限制的问题。

  SAF存储访问框架介绍

  SAF介绍链接

  Android 4.4（API 级别 19）引入了存储访问框架 (SAF)。SAF 让用户能够在其所有首选文档存储提供程序中方便地浏览并打开文档、图像以及其他文件。 用户可以通过易用的标准 UI，以统一方式在所有应用和提供程序中浏览文件和访问最近使用的文件。

  针对SD Card文件访问读写受限制的问题。

  自API 19引入SAF后，应用程序无法直接通过java 的File API进行写操作了。需要用到Android 的DocumentFile API 进行间接处理文件。

  • 首先需要获取SD Card的读写权限
  • 在获取的URI权限基础上创建DocumentFile.fromTreeUri(context,uri)
  • 根据获取到的权限目录树进行子文件或子文件夹操作，类似于JAVA的File操作。
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• Public An aar library to JCenter and MavenCenter

  2018-09-23

  Android  Jcenter  Maven

  JCenter  Maven  Gradle
  • Introduction
    • Jcenter And Maven Center
    • Example Project
    • Android Gradle automated publish an aar library
      • Add buildScript to dependencies
      • apply plugin at library module
      • For maven ,we need sources.Jar and javadoc.Jar artifacts
      • Bintray configuration:

  Introduction

  Jcenter And Maven Center

  Jcenter and MavenCenter are moden time standar maven center. they maintained by Bintray and sonatype respectively.

  As the artical , we just talk abut Bintray’s JCenter. Cause Android Studio now support Jcenter as default maven center.

  First of all , you need create an accunt of Binray at Bintray.com and generate an API Key at Edit menu of account profile

  Example Project

  

  MvpArch

  Android Gradle automated publish an aar library

  Add buildScript to dependencies

  buildscript{
      dependencies{
          //bintray: jcenter publish build plugin
  		classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.8.4'
      }
  }
      
  

  apply plugin at library module

  apply plugin: 'com.jfrog.bintray'
  apply plugin: 'maven-publish'// maven publish method  to create groups of artifacts
  

  The bintray plugin supports three methods to create groups of artifacts: Configurations, Publications and Copying specific files using filesSpec. For more read, reference gradle-bintray-plugin.

  For maven ,we need sources.Jar and javadoc.Jar artifacts

  create task as below for android gradle:

    
    task sourcesJar(type: Jar) {
        from android.sourceSets.main.java.srcDirs
        classifier = 'sources'
    }
    
    task javadoc(type: Javadoc) {
        source = android.sourceSets.main.java.srcDirs
        classpath += project.files(android.getBootClasspath().join(File.pathSeparator))
    }
    
    task javadocJar(type: Jar, dependsOn: javadoc) {
        classifier = 'javadoc'
        from javadoc.destinationDir
    }
    
    artifacts {
        archives javadocJar
        archives sourcesJar
    }
  

  Bintray configuration:

  Read All

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• Android 接入firebase

  2018-08-15

  Android  firebase  gradle

  Android  Firebase

  注册firebase账号

  在firebse 上注册登陆账号，之后注册应用，填写包名等信息，下载配置文件。

  下载配置文件

  google-services.json

  添加 Firebase SDK

  适用于 Gradle 的说明

  UnityC++Gradle 的 Google 服务插件会加载您刚刚下载的 google-services.json 文件。请修改您的 build.gradle 文件以使用该插件。

  项目级 build.gradle（<项目>/build.gradle）：

  buildscript { 
  
  dependencies { 
  
  // Add this line 
  
  classpath 'com.google.gms:google-services:4.0.0' } 
  
  } 
  

  应用级 build.gradle（<项目>/<应用模块>/build.gradle）：

  dependencies {
    // Add this line
    compile 'com.google.firebase:firebase-core:16.0.0'
  }
  ...
  // Add to the bottom of the file
  apply plugin: 'com.google.gms.google-services'
  

  默认情况下包含 Analytics

  最后，按 IDE 中显示的栏中的“立即同步”：

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• Android Gradle build 构建脚本语法用法

  2018-08-15

  Android  Gradle

  Android  Gradle  groovy
  • Android 构建脚本简介

  Android 构建脚本简介

  Android APP 构建脚本采用的是Gradle框架。Gradle是一种构建builde编译框架，采用的是groovy语言。谷歌官方有使用自己的一套builde 插件依赖 配置在project.gradle文件里：

  buildscript {
      repositories {
          jcenter()
          google()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:3.0.1'
                 
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  

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• bundle-install-for-jekyll

  2018-07-27

  gem  jekyll  gem-bundle

  gem  jekyll  gem-bundle
  • Problems on linux when using gem bundle install

  Problems on linux when using gem bundle install

  As following:

  Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
      current directory: /home/jaysen/gems/gems/nokogiri-1.8.4/ext/nokogiri
  /usr/bin/ruby2.5 -r ./siteconf20180727-12716-1rv24w0.rb extconf.rb
  checking if the C compiler accepts ... yes
  Building nokogiri using packaged libraries.
  Using mini_portile version 2.3.0
  checking for gzdopen() in -lz... no
  zlib is missing; necessary for building libxml2
  *** extconf.rb failed ***
  Could not create Makefile due to some reason, probably lack of necessary
  libraries and/or headers.  Check the mkmf.log file for more details.  You may
  need configuration options.
  
  Provided configuration options:
  	--with-opt-dir
  	--without-opt-dir
  	--with-opt-include
  	--without-opt-include=${opt-dir}/include
  	--with-opt-lib
  	--without-opt-lib=${opt-dir}/lib
  	--with-make-prog
  	--without-make-prog
  	--srcdir=.
  	--curdir
  	--ruby=/usr/bin/$(RUBY_BASE_NAME)2.5
  	--help
  	--clean
  	--use-system-libraries
  	--enable-static
  	--disable-static
  	--with-zlib-dir
  	--without-zlib-dir
  	--with-zlib-include
  	--without-zlib-include=${zlib-dir}/include
  	--with-zlib-lib
  	--without-zlib-lib=${zlib-dir}/lib
  	--enable-cross-build
  	--disable-cross-build
  
  To see why this extension failed to compile, please check the mkmf.log which can
  be found here:
  
    /home/jaysen/gems/extensions/x86_64-linux/2.5.0/nokogiri-1.8.4/mkmf.log
  
  extconf failed, exit code 1
  
  Gem files will remain installed in /home/jaysen/gems/gems/nokogiri-1.8.4 for
  inspection.
  Results logged to
  /home/jaysen/gems/extensions/x86_64-linux/2.5.0/nokogiri-1.8.4/gem_make.out
  
  An error occurred while installing nokogiri (1.8.4), and Bundler cannot
  continue.
  Make sure that `gem install nokogiri -v '1.8.4' --source
  'https://rubygems.org/'` succeeds before bundling.
  
  In Gemfile:
    github-pages was resolved to 188, which depends on
      jekyll-mentions was resolved to 1.4.0, which depends on
        html-pipeline was resolved to 2.8.3, which depends on
          nokogiri
  

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