最近刚使用android studio开发android的APP，由于我工作中的项目用到了native开发，所以需要在android studio中构建APP的ndk编译环境。首先，我使用的是android studio 1.1.0 版本以及ndk-r10d，这个版本必须使用ndk-r10d，至于为什么，可以到android官网查看一下资料。
ndk的安装过程百度应该可以找到，这里我们就不讲了。关键是在学习android studio过程中的一些gradle的心得以及一些问题。
下面是我的app模块下的gradle配置：
apply plugin: 'com.android.application'
android {
compileSdkVersion 22
buildToolsVersion "22.0.1"
defaultConfig {
applicationId "com.big.pv.bigsuperuser"
minSdkVersion 19
targetSdkVersion 22
versionCode 1
versionName "1.0"
ndk {
moduleName "onehook"//模块名称
abiFilters "armeabi", "armeabi-v7a", "x86"
cFlags "-std=gnu++11 -fpermissive -DDEBUG -O0"
// ldLibs "-llog -landroid_runtime -lutils -lcutils -lart -ldvm"
ldLibs "log","android_runtime","utils","cutils","art","dvm"
stl "gnustl_static"
}
// sourceSets.main {
// jni.srcDirs = []
// jniLibs.srcDir 'src/main/libs'
// }
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:22.1.1'
}
其实这个编译工具是java的，我们很容易的从ADK工具中找到他们的Declaration部分，就是对着code右键选择go to -> Declaration或者快捷键xxxx即可。
我们来一层层的分析吧。
第一行 apply plugin: 'com.android.application' 可以看出我们要构建的项目是一个android 的app
首先我们开始看第一个标签android{}他所在的包的位置是package com.android.build.gradle;
我们打开他的Declaration部分是如下的：
// IntelliJ API Decompiler stub source generated from a class file
// Implementation of methods is not available
package com.android.build.gradle;
public class AppExtension extends com.android.build.gradle.BaseExtension implements groovy.lang.GroovyObject {
private final org.gradle.api.internal.DefaultDomainObjectSet<com.android.build.gradle.api.ApplicationVariant> applicationVariantList;
public AppExtension(@com.android.annotations.NonNull org.gradle.api.internal.project.ProjectInternal project, @com.android.annotations.NonNull org.gradle.internal.reflect.Instantiator instantiator, @com.android.annotations.NonNull com.android.builder.core.AndroidBuilder androidBuilder, @com.android.annotations.NonNull com.android.build.gradle.internal.SdkHandler sdkHandler, @com.android.annotations.NonNull org.gradle.api.NamedDomainObjectContainer<com.android.build.gradle.internal.dsl.BuildType> buildTypes, @com.android.annotations.NonNull org.gradle.api.NamedDomainObjectContainer<com.android.build.gradle.internal.dsl.GroupableProductFlavor> productFlavors, @com.android.annotations.NonNull org.gradle.api.NamedDomainObjectContainer<com.android.build.gradle.internal.dsl.SigningConfig> signingConfigs, @com.android.annotations.NonNull com.android.build.gradle.internal.ExtraModelInfo extraModelInfo, boolean isLibrary) { /* compiled code */ }
public org.gradle.api.internal.DefaultDomainObjectSet<com.android.build.gradle.api.ApplicationVariant> getApplicationVariants() { /* compiled code */ }
public void addVariant(com.android.build.gradle.api.BaseVariant variant) { /* compiled code */ }
}
看他继承自 extends com.android.build.gradle.BaseExtension，我们通过android{compileSdkVersion 22}里面的项compileSdkVersion再goto一下Declaration，可以发现android{这里的项都是来自BaseExtension继承的属性或函数}，这样我们就可以顺藤摸瓜，找到所有的apply plugin: 'com.android.application'构建的声明解释，从找到我们想要的编译方法。
==================================================
下面是我遇到的一个关于NDK编译的问题，NDK这个项是在defaultConfig或buildTypes里，下面是NdkOption的代码：
/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* f4dK9s2c8@1M7q4)9K6b7g2)9J5c8W2)9J5c8Y4N6%4N6#2)9J5k6h3q4H3j5h3y4Z5k6g2)9J5k6h3!0J5k6#2)9J5c8X3I4A6j5$3g2F1M7$3g2K6i4K6u0r3e0p5W2o6c8f1&6e0c8g2)9J5k6o6u0Q4x3X3f1H3
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.build.gradle.internal.dsl;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.build.gradle.internal.core.NdkConfig;
import com.google.common.collect.Sets;
import org.gradle.api.tasks.Input;
import org.gradle.api.tasks.Optional;
import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
/**
* DSL object for NDK-related settings.
*/
public class NdkOptions implements NdkConfig, Serializable {
private static final long serialVersionUID = 1L;
private String moduleName;
private String cFlags;
private Set<String> ldLibs;
private Set<String> abiFilters;
private String stl;
public NdkOptions() {
}
public NdkOptions(@NonNull NdkOptions ndkConfig) {
moduleName = ndkConfig.moduleName;
cFlags = ndkConfig.cFlags;
setLdLibs(ndkConfig.ldLibs);
setAbiFilters(ndkConfig.abiFilters);
}
@Override
@Input @Optional
public String getModuleName() {
return moduleName;
}
public void setModuleName(String moduleName) {
this.moduleName = moduleName;
}
@Override
@Input @Optional
public String getcFlags() {
return cFlags;
}
public void setcFlags(String cFlags) {
this.cFlags = cFlags;
}
@Override
@Input @Optional
public Set<String> getLdLibs() {
return ldLibs;
}
@NonNull
public NdkOptions ldLibs(String lib) {
if (ldLibs == null) {
ldLibs = Sets.newHashSet();
}
ldLibs.add(lib);
return this;
}
@NonNull
public NdkOptions ldLibs(String... libs) {
if (ldLibs == null) {
ldLibs = Sets.newHashSetWithExpectedSize(libs.length);
}
Collections.addAll(ldLibs, libs);
return this;
}
@NonNull
public NdkOptions setLdLibs(Collection<String> libs) {
if (libs != null) {
if (abiFilters == null) {
abiFilters = Sets.newHashSetWithExpectedSize(libs.size());
} else {
abiFilters.clear();
}
for (String filter : libs) {
abiFilters.add(filter);
}
} else {
abiFilters = null;
}
return this;
}
@Override
@Input @Optional
public Set<String> getAbiFilters() {
return abiFilters;
}
@NonNull
public NdkOptions abiFilter(String filter) {
if (abiFilters == null) {
abiFilters = Sets.newHashSetWithExpectedSize(2);
}
abiFilters.add(filter);
return this;
}
@NonNull
public NdkOptions abiFilters(String... filters) {
if (abiFilters == null) {
abiFilters = Sets.newHashSetWithExpectedSize(2);
}
Collections.addAll(abiFilters, filters);
return this;
}
@NonNull
public NdkOptions setAbiFilters(Collection<String> filters) {
if (filters != null) {
if (abiFilters == null) {
abiFilters = Sets.newHashSetWithExpectedSize(filters.size());
} else {
abiFilters.clear();
}
for (String filter : filters) {
abiFilters.add(filter);
}
} else {
abiFilters = null;
}
return this;
}
@Override
@Nullable
public String getStl() {
return stl;
}
public void setStl(String stl) {
this.stl = stl;
}
}
从代码中基本上可以解决NDK的编译配置问题了。但是我的项目里用到了APP_STL，可无论我怎么设置，他都不会在build后的ndk目录下的Android.mk内生成APP_STL，想请教一下，这个APP_STL该如何生成，顺便想问问如果定义NDK的目标版本？比方说android-19.我也找不到gradle内如何配置才能产生此编译项。
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