Android Gradle語法（Android Gradle DSL）

Google關於Android Gradle DSL的官方文檔：
Android Gradle DSL

一、cmake

下面由兩個cmake語句，但其類型不同，所以其屬性不同

1、CmakeOptions類型的cmake

路徑：
(AppExtension) android->
(ExternalNativeBuild) externalNativeBuild ->
(CmakeOptions) cmake

android {
		externalNativeBuild {
				cmake {
						buildStagingDirectory "./outputs/cmake"
						path "CMakeLists.txt"
						version "3.7.1"
				}
		}
}

AppExtension :The android extension for application plugins.
即，android{ 這裏使用 }

Property	Description
buildStagingDirectory	Specifies the path to your external native build output directory.
path	Specifies the relative path to your CMakeLists.txt build script.
version	The version of CMake that the Android plugin should use when building your CMake project.

2、ExternalNativeCmakeOptions類型的cmake

路徑：
(AppExtension) android->
(DefaultConfig) defaultConfig->
(ExternalNativeBuildOptions) externalNativeBuild->
(ExternalNativeCmakeOptions) cmake

android {
		defaultConfig {
				externalNativeBuild {
						cmake {
								arguments "-DANDROID_ARM_NEON=TRUE", "-DANDROID_TOOLCHAIN=clang"
								cFlags "-D__STDC_FORMAT_MACROS"
								cppFlags "-fexceptions", "-frtti"
								targets "libexample-one"
						}
				}
		}
}

Property	Description
abiFilters	Specifies the Application Binary Interfaces (ABI) that Gradle should build outputs for. The ABIs that Gradle packages into your APK are determined by NdkOptions.abiFilter()
arguments	Specifies arguments for CMake.
cFlags	Specifies flags for the C compiler.
cppFlags	Specifies flags for the C++ compiler.
targets	Specifies the library and executable targets from your CMake project that Gradle should build. If you don’t configure this property, Gradle builds all executables and shared object libraries that you define in your ndk-build project. However, by default, Gradle packages only the shared libraries in your APK.

通過targets屬性的描述可知，默認只打包“動態庫文件”，即.so文件。
如果希望生成“靜態庫文件”，即.a文件，則需要加上targets屬性來指明靜態庫名。