Android基础知识学习

一.Android编译过程

• 初始化参数设置
• 检查环境变量与目标环境
• 选择lunch并读取目标配置和平台信息
• 清空输出目录
• 编译
• 生成升级包

二. ./build/envsetup.sh分析

• 加载编译命令：source ./build/envsetup.sh
• 加载平台信息：lunch平台信息；export查看环境变量

三.Android.mk

• native层(可执行文件、动态库、静态库)；Java层(Jar包、Apk)；组成android编译基本语法规则

Android.mk简例

LOCAL_PATH := $(call my-dir)  #LOCAL_PATH定义在build/core/definitons.mk,定义当前模块相对路径
include $(CLEAR_VARS)  #CLEAR_VAR定义在build/core/cler_vars.mk,表示清空除loal_path外的环境变量
LOCAL_MODULE := test   #编译生成名称
LOCAL_SRC_FILES := test.c  #源文件
LOCAL_MODULE_PATH := $(LOCAL_PATH)  #指定输出路径
include $(BUILD_EXECUTABLE)  #生成格式，这里是编程生成二进制文件

• Android.mk深度学习1：多源码文件编译、一个.mk中编译多个目标文件、编译动态库、编译静态库

Android.mk 简例:增加源文件__将每个文件添加到.mk中

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := test   
LOCAL_SRC_FILES := src/main.c \    #增加多源文件，将每个文件添加到.mk中
                   src/test1.c \
                   src/test2.c
  
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE)

Android.mk 简例:增加源文件__使用系统提供的函数处理

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := test   
LOCAL_C_ALL_FILES := $(call all-c-files-under)  #取所有.c文件
LOCAL_SRC_FILES := $(LOCAL_C_ALL_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE)

Android.mk 简例:一个mk文件编译多个目标文件

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := test   #目标文件test
LOCAL_C_ALL_FILES := $(call all-c-files-under)  #取所有.c文件
LOCAL_SRC_FILES := $(LOCAL_C_ALL_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE)

include $(CLEAR_VARS)  
LOCAL_MODULE := test1   #目标文件test1
LOCAL_C_ALL_FILES := $(call all-c-files-under)  #取所有.c文件
LOCAL_SRC_FILES := $(LOCAL_C_ALL_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE)

Android.mk 简例:编译生成动态库

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := libtest  
LOCAL_C_ALL_FILES := src/test1.c \
                     src/test2.c
LOCAL_SRC_FILES := $(LOCAL_C_ALL_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_SHARED_LIBRARY)    #编译生成动态库

Android.mk 简例:编译生成静态库

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := libtest  
LOCAL_C_ALL_FILES := src/test1.c \
                     src/test2.c
LOCAL_SRC_FILES := $(LOCAL_C_ALL_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_STATIC_LIBRARY)    #编译生成静态库

• Android.mk深度学习2：如何引入系统库、如何引入第三方库、如何引入静态库、如何进入头文件

Android.mk 简例:项目中引入系统库

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := test  
LOCAL_SRC_FILES := src/main.cpp
LOCAL_SHARED_LIBRARIES += liblog   #链入系统log库
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE)    

Android.mk 简例:加载第三方库

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := libtest  
LOCAL_SRC_FILES := src/test.cpp
LOCAL_MODULE_PATH := $(LOCAL_PATH)/lib 
include $(BUILD_SHARED_LIBRARY)  

include $(CLEAR_VARS)  
LOCAL_MODULE := test 
LOCAL_LDFLAGS :=-L./lib -ltest  #加载当前目录下的第三方库
LOCAL_SRC_FILES := src/main.cpp   #调用了test.cpp接口 
LOCAL_SHARED_LIBRARIES += liblog   
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE)  

Android.mk 简例:引入第三方头文件

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := libtest  
LOCAL_SRC_FILES := src/test.cpp
LOCAL_MODULE_PATH := $(LOCAL_PATH)/lib 
include $(BUILD_SHARED_LIBRARY)  

include $(CLEAR_VARS)  
LOCAL_MODULE := test 
LOCAL_C_INCLUDES :=$(LOCAL_PATH)/inc
LOCAL_LDFLAGS :=-L./lib -ltest  #加载当前目录下的第三方库
LOCAL_SRC_FILES := src/main.cpp   #调用了test.cpp接口 
LOCAL_SHARED_LIBRARIES += liblog   
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE) 

Android.mk 简例:引入静态库

LOCAL_PATH := $(call my-dir) 
include $(CLEAR_VARS)  
LOCAL_MODULE := libtest  
LOCAL_SRC_FILES := src/test.cpp
LOCAL_MODULE_PATH := $(LOCAL_PATH)/lib 
include $(BUILD_SHARED_LIBRARY)  

include $(CLEAR_VARS)  
LOCAL_MODULE := test 
LOCAL_C_INCLUDES :=$(LOCAL_PATH)/inc
LOCAL_LDFLAGS := $(LOCAL_PATH)/lib/libtest1.a
LOCAL_SRC_FILES := src/main.cpp   #调用了test.cpp接口 
LOCAL_SHARED_LIBRARIES += liblog   
LOCAL_MODULE_PATH := $(LOCAL_PATH)/bin 
include $(BUILD_EXECUTABLE) 

• Android.mk深度学习3：如何编译jar包、如何编译Apk、Apk中导入jar包和库文件、mk中如何加判断语句

Android.mk编译生成Apk

LOCAL_PATH := $(call my-dir)  
include $(CLEAR_VARS) 
LOCAL_MODULE_TAGS := optional
LOCAL_STATIC_JAVA_LIBRARIES := libarity android-support-v4 guava
LOCAL_SRC_FILES := $(call all-subdir-java-files)
LOCAL_SDK_VERSION := current
LOCAL_PACKAGE_NAME := Calculator   #编译生成apk名字
include $(BUILD_PACKAGE)   #编译生成apk

Android.mk编译生成jar

LOCAL_PATH := $(call my-dir)  
include $(CLEAR_VARS) 
LOCAL_SRC_FILES := $(call all-subdir-java-files)
LOCAL_MODULE := com.test.myjar
include $(BUILD_STATIC_JAVA_LIBRARY)   #编译生成静态jar包
若是-》include $(BUILD_JAVA_LIBRARY)   #编译生成共享jar包

判断
ifeq/ifneq:根据判断条件执行相关编译

四.Android启动过程

 

学习视频路径：https://www.bilibili.com/video/BV1mb411872F?from=search&seid=13706101650228050770

本文地址：https://blog.csdn.net/qq_39481566/article/details/110294004