如何用Android Studio和Gradle构建Android库？

Question

我已经将整个项目上传到了GitHub https://GitHub.com/respectthecode/android-studio-library-example

更新1

根据帕德玛·库马尔的建议，这就是我所尝试的。

null

Module "MyLib" was fully rebuilt due to project configuration/dependencies changes
Compilation completed with 1 error and 0 warnings in 19 sec
1 error
0 warnings
/.../MyApp/MyLib/build/bundles/debug/AndroidManifest.xml
Gradle: <manifest> does not have package attribute.

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.mylib" >

在构建之后，我得到了这个错误

Module "MyApp" was fully rebuilt due to project configuration/dependencies changes
Compilation completed with 2 errors and 0 warnings in 13 sec
2 errors
0 warnings
/.../MyApp/MyLib/src/main/java/com/example/mylib/MainActivity.java
Gradle: package R does not exist
Gradle: package R does not exist

添加依赖项似乎不会对错误产生任何影响。从上面继续

1. 单击文件>项目结构>模块>myapp-myapp
2. 切换到依赖项选项卡
3. 单击+>Module dependency并选择mylib
4. 单击应用和确定
5. 单击生成>生成项目

根据伊森的建议，这就是我们得到的

2个子项目build.gradle似乎有所有正确的部分，唯一的区别是插件行，下面是myapp/build.gradle。

buildscript {
    repositories {
        maven { url 'http://repo1.maven.org/maven2' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.4'
    }
}
apply plugin: 'android'

dependencies {
    compile files('libs/android-support-v4.jar')
}

android {
    compileSdkVersion 17
    buildToolsVersion "17.0.0"

    defaultConfig {
        minSdkVersion 7
        targetSdkVersion 16
    }
}

根项目build.gradle为空，因此我添加了这两个项目，如下所示

dependencies {
    compile project(":MyLib")
    compile project(":MyApp")
}

Gradle:
FAILURE: Build failed with an exception.
* Where:
Build file '/Users/kevin/GitHub/AppPress/MyApp/build.gradle' line: 2
* What went wrong:
A problem occurred evaluating root project 'MyApp'.
> Could not find method compile() for arguments [project ':MyLib'] on root project 'MyApp'.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

非常感谢伊森解决了这件事。

1. 将编译项目(':subprojects:mylib')添加到mylib/build.gradle
2. 从mylib/build.gradle
中删除 编译文件（“libs/android-support-v4.jar”）
3. 关闭项目并从Gradle导入根项目

更新4

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:0.4.2'
    }
}

apply plugin: 'android'

dependencies {
    compile "com.android.support:support-v4:13.0.0"

    compile project(':SubProjects:MyLib')
}

Answer 1

注意：这个答案是一个纯粹的分级答案，我经常在IntelliJ中使用这个答案，但我不知道与Android Studio的集成情况如何。我是一个相信知道对我来说正在发生什么的人，所以这就是我使用Gradle和Android的方式。

TL；DR完整示例-https://github.com/ethankhall/driving-time-tracker/

免责声明：这是我正在/正在做的一个项目。

Project Root
+-- src
|   +-- main (your project)
|   |   +-- java (where your java code goes)
|   |   +-- res  (where your res go)
|   |   +-- assets (where your assets go)
|   |   \-- AndroidManifest.xml
|   \-- instrumentTest (test project)
|       \-- java (where your java code goes)
+-- build.gradle
\-- settings.gradle

Build.Gradle

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.3'
    }
}

现在我们需要告诉Gradle关于Android的一些部分。这相当简单.一个基本的（在我的大多数情况下都适用）如下所示。我在这个块中有一个注释，它将允许我在生成APK时指定版本名和代码。

Build.Gradle

apply plugin: "android"
android {
        compileSdkVersion 17
        /*
        defaultConfig {
            versionCode = 1
            versionName = "0.0.0"
        }
        */
    }

task wrapper(type: org.gradle.api.tasks.wrapper.Wrapper) {
    gradleVersion = '1.4'
}

Project Root
+-- src (see above)
+-- subProjects (where projects are held)
|   +-- reallyCoolProject1 (your first included project)
|       \-- See project structure for a normal app
|   \-- reallyCoolProject2 (your second included project)
|       \-- See project structure for a normal app
+-- build.gradle
\-- settings.gradle

设置。分级：

include ':subProjects:reallyCoolProject1'
include ':subProjects:reallyCoolProject2'

您应该确保的最后一件事是子项目/reallycoolproject1/build.gradle有apply plugin：“android-library”而不是apply plugin：“android”。

像每个Gradle项目（和Maven）一样，我们现在需要告诉根项目它的依赖关系。这也可以包括您想要的任何正常Java依赖项。

dependencies{
    compile 'com.fasterxml.jackson.core:jackson-core:2.1.4'
    compile 'com.fasterxml.jackson.core:jackson-databind:2.1.4'
    compile project(":subProjects:reallyCoolProject1")
    compile project(':subProjects:reallyCoolProject2')
}

NDK侧注：如果你要使用NDK，你将需要类似下面的东西。build.gradle文件示例可在以下位置找到：https://gist.github.com/khernyo/4226923

Build.Gradle

task copyNativeLibs(type: Copy) {
    from fileTree(dir: 'libs', include: '**/*.so' )  into  'build/native-libs'
}
tasks.withType(Compile) { compileTask -> compileTask.dependsOn copyNativeLibs }

clean.dependsOn 'cleanCopyNativeLibs'

tasks.withType(com.android.build.gradle.tasks.PackageApplication) { pkgTask ->
  pkgTask.jniDir new File('build/native-libs')
}

资料来源：

null