Android Studio 在 Windows 中用 C++ 链接外部库

Question

有人可以向我解释如何在 ndk 项目中正确链接用 C++ 编写的外部库吗？

我正在尝试使用本视频中描述的 SDL 库：https://www.youtube.com/watch?v=BSBISI0sCqo&t=306s，但是当我尝试在终端中执行其中一个命令时出现问题：

F:/Programming/Android/Indie/app/src/main/cpp> C:/Users/Danijel/AppData/Local/Android/sdk/ndk-bundle/ndk-build NDK_LIBS_OUT=../jniLibs

此调用导致错误：

Android NDK：未设置 APP_PLATFORM。默认为支持的最低版本 android- 14. Android NDK：您的 APP_BUILD_SCRIPT 指向一个未知文件：F:/Programming/Android/Indie/app/src/main/cpp/jni/Android.mk C:/Users/Danijel/AppData/Local/Android/sdk/ndk-bundle/build//../build/core/add-appl ication.mk:101: *** Android NDK: 中止......停下来。

所以，我知道实际路径包含 cpp 文件夹（我无法将其重命名为 jni），而不是 jni，但是当我尝试在 gradle 中设置路径时也会发生同样的事情。

folder structure

Android.mk：

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE    := app
LOCAL_CFLAGS    := -Wall -Wextra
LOCAL_SRC_FILES := BoardManager.cpp GameEnvironment.cpp GameObject.cpp Player.cpp Renderer.cpp ShaderManager.cpp Utility.cpp TextureManager.cpp
LOCAL_LDLIBS := -lGLESv1_CM -ldl -llog
include $(BUILD_SHARED_LIBRARY)

应用程序.mk：

APP_PLATFORM=android-14
APP_ABI := armeabi-v7a
APP_STL := gnustl_static

CMakeLists.txt：

# Sets the minimum version of CMake required to build the native
# library. You should either keep the default value or only pass a
# value of 3.4.0 or lower.

cmake_minimum_required(VERSION 3.4.1)

# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds it for you.
# Gradle automatically packages shared libraries with your APK.

if (${ANDROID_PLATFORM_LEVEL} LESS 12)
  message(FATAL_ERROR "OpenGL 2 is not supported before API level 11 (currently using ${ANDROID_PLATFORM_LEVEL}).")
  return()
elseif (${ANDROID_PLATFORM_LEVEL} LESS 18)
  add_definitions("-DDYNAMIC_ES3")
  set(OPENGL_LIB GLESv2)
else ()
  set(OPENGL_LIB GLESv3)
endif (${ANDROID_PLATFORM_LEVEL} LESS 11)

include_directories(src/main/cpp/)

add_library( # Sets the name of the library.
             native-lib

             # Sets the library as a shared library.
             SHARED

             # Provides a relative path to your source file(s).
             # Associated headers in the same location as their source
             # file are automatically included.
             src/main/cpp/native-lib.cpp
             src/main/cpp/BoardManager.cpp
             src/main/cpp/GameEnvironment.cpp
             src/main/cpp/GameObject.cpp
             src/main/cpp/Player.cpp
             src/main/cpp/Renderer.cpp
             src/main/cpp/ShaderManager.cpp
             src/main/cpp/Utility.cpp
             src/main/cpp/TextureManager.cpp )

# Searches for a specified prebuilt library and stores the path as a
# variable. Because system libraries are included in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.

find_library( # Sets the name of the path variable.
              log-lib

              # Specifies the name of the NDK library that
              # you want CMake to locate.
              log )

# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in the
# build script, prebuilt third-party libraries, or system libraries.

target_link_libraries( # Specifies the target library.
                       native-lib
                       ${OPENGL_LIB}
                       EGL
                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} )

Answer 1

C:/Users/Danijel/AppData/Local/Android/sdk/ndk-bundle/build//../build/core/add-appl ication.mk:101: *** Android NDK: Aborting... . Stop.

add-appl ication.mk中有一个空格