android 纯c/c++开发（转）

转载自： http://jingyan.baidu.com/article/a501d80cf394dfec630f5e85.html

android 自ndk r8出来以后，就开始支持纯c/c++开发，android 的纯 c/c++ 开发更有些想 win32 开发，只不过是 WinMain 变成了 android_main, 消息处理函数变成了两个，下面开始详细的介绍如何进行纯 c/c++开发，里面附带一个多点触屏的例子，希望对大家有用，谢谢！

工具/原料

win7 x64
jdk1.8.0_11
adt-bundle-windows-x86_64-20140702
android-ndk-r10

新建一个Natvie工程

1

打开eclipse；
2

打开菜单->File->New->Android Application；
3

设置工程名，sdk版本，注意：主题设置为 None，点击next；
4

Configure Project 是取消 Create activity 的复选框，点击next；
5

Configure the attributes of the icon set，直接点击 next；
6

Select whether to create an activity, and if so, what kind of activity. 点击 finish即可；
7

工程便创建出来了

END

配置Makefile

1

右键工程NativeTest->弹出菜单->Android Tools->Add Native Support...
2

Settings for generated native components for project.界面直接点击Finish
3

将 android.mk 的内容补充完整：

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE := NativeTest

LOCAL_SRC_FILES := NativeTest.cpp

LOCAL_LDLIBS := -llog -landroid

LOCAL_STATIC_LIBRARIES := android_native_app_glue

include $(BUILD_SHARED_LIBRARY)

$(call import-module,android/native_app_glue)
4

增加一个 Application.mk 文件（这一步可选），并写入：

APP_ABI := x86

APP_CPPFLAGS := --std=c++11

NDK_TOOLCHAIN_VERSION := 4.8

END

代码部分

1

1、android_main：这个函数类似于win32开发的WinMain函数

2、app->onAppCmd = onAppCmd;

app->onInputEvent = onInputEvent;

类似于win32中设置窗口的回掉函数

3、

while ((ident=ALooper_pollAll(-1, NULL, &events,

(void**)&source)) >= 0) {

// Process this event.

if (source != NULL) {

source->process(app, source);

}

// Check if we are exiting.

if (app->destroyRequested != 0) {

return;

}

}

这一段类似于win32的消息循环

4、为了方便大家粘贴，android_main 函数的代码如下：

void android_main(struct android_app* app) {

// Make sure glue isn't stripped.

app_dummy();

app->onAppCmd = onAppCmd;

app->onInputEvent = onInputEvent;

while (1) {

int ident;

int events;

struct android_poll_source* source;

while ((ident=ALooper_pollAll(-1, NULL, &events,

(void**)&source)) >= 0) {

// Process this event.

if (source != NULL) {

source->process(app, source);

}

// Check if we are exiting.

if (app->destroyRequested != 0) {

return;

}

}

}

}
2

onAppCmd 描述的是真个activity的生命周期，类似于win32开发的消息处理回掉函数：

static void onAppCmd(struct android_app* app, int32_t cmd) {

switch (cmd) {

case APP_CMD_SAVE_STATE:

// The system has asked us to save our current state. Do so.

__android_log_print(ANDROID_LOG_DEBUG, "fuke", "engine_handle_cmd APP_CMD_SAVE_STATE");

break;

case APP_CMD_INIT_WINDOW:

// The window is being shown, get it ready.

__android_log_print(ANDROID_LOG_DEBUG, "fuke", "engine_handle_cmd APP_CMD_INIT_WINDOW");

break;

case APP_CMD_TERM_WINDOW:

__android_log_print(ANDROID_LOG_DEBUG, "fuke", "engine_handle_cmd APP_CMD_TERM_WINDOW");

break;

case APP_CMD_GAINED_FOCUS:

// When our app gains focus, we start monitoring the accelerometer.

__android_log_print(ANDROID_LOG_DEBUG, "fuke", "engine_handle_cmd APP_CMD_GAINED_FOCUS");

break;

case APP_CMD_LOST_FOCUS:

// When our app loses focus, we stop monitoring the accelerometer.

// This is to avoid consuming battery while not being used.

__android_log_print(ANDROID_LOG_DEBUG, "fuke", "engine_handle_cmd APP_CMD_LOST_FOCUS");

break;

}

}
3

onInputEvent 主要是用来触屏相关事件，也类似于win32开发的消息处理回掉函数，函数有两部分组成：

1、检测多点触屏，并通过logcat打印出多点触屏的信息；

2、控制屏幕颜色变化，每次松开手时颜色变化

3、为方便大家粘贴，onInputEvent函数的代码记录如下：

static int32_t onInputEvent(struct android_app* app, AInputEvent* event) {

if (AInputEvent_getType(event) == AINPUT_EVENT_TYPE_MOTION) {

int nNum = AMotionEvent_getPointerCount(event);

char szTrace[1024] = {0};

sprintf (szTrace, "engine_handle_input num=[%d]", nNum);

for (int nIdx = 0; nIdx < nNum; nIdx++)

{

int nX = AMotionEvent_getX(event, 0);

int nY = AMotionEvent_getY(event, 0);

sprintf (strrchr(szTrace, 0), " (%d %d)", nX, nY);

}

__android_log_print(ANDROID_LOG_DEBUG, "colorspace",

"%s", szTrace);

if (AKeyEvent_getAction(event) != AKEY_EVENT_ACTION_UP)

return 1;

ANativeWindow_Buffer nativeWindow = {0};

int nRet = ANativeWindow_lock(app->pendingWindow, &nativeWindow, NULL);

int nArea = nativeWindow.width * nativeWindow.height;

unsigned long* pdwScreen = (unsigned long*)nativeWindow.bits;

static int s_nClr = 0;

unsigned long pdwClr[] = {

0x00000000, 0x000000ff, 0x0000ffff, 0x0000ff00,

0x00ffff00, 0x00ff0000, 0x00ff00ff, 0x00ffffff};

s_nClr ++;

if (s_nClr > sizeof(pdwClr) / sizeof(unsigned long))

s_nClr = 0;

for (int nIdx = 0; nIdx < nArea; nIdx++)

{

pdwScreen[nIdx] = pdwClr[s_nClr];

}

ANativeWindow_unlockAndPost(app->pendingWindow);

return 1;

}

return 0;

}

END

设置工程属性

1

1、打开 AndroidManifest.xml

2、打开 Application 分页

3、增加一个 Activity

如下所示：
2

1、选择右边的 Browse;

2、取消 "Display classes from sources of ..." 前面的复选框;

3、在搜索栏输入"na"，选中列出来的 "NativeActivity"

4、点击OK

效果如下：
3

1、选中 android.app.nativeActivity

2、点击 add

3、选择 Meta Data

4、点击Ok
4

输入：

android:name="android.app.lib_name"

android:value="NativeTest"
5

1、选中 android.app.nativeActivity

2、点击 add

3、选择 Intent Filter

4、点击Ok
6

1、选中 Intent Filter

2、点击 add

3、选择 Action

4、点击Ok

5、设置 android:name="android.intent.action.MAIN"
7

1、选中 Intent Filter

2、点击 add

3、选择 Category

4、点击Ok

5、设置 android:name="android.intent.category.LAUNCHER"

END