用鸿蒙开发AI应用（七）触摸屏控制LED 原创 精华
前言
上一篇，我们体验了一下鸿蒙上的界面的开发流程，这一篇我们继续深入一点点，尝试打通从用户态UI到内核态HDF之间的联系。其中涉及到的调用关系比较复杂，建议在“用鸿蒙开发AI应用（五）HDF 驱动补光灯”的基础上阅读本文，HDF的相关细节这里就不在赘述了。
背景知识
用户程序框架子系统包含两个大的模块：Ability子系统和包管理子系统。
1. Ability子系统
1.1 Ability
Ability是系统调度应用的最小单元，是能够完成一个独立功能的组件，一个应用可以包含一个或多个Ability。Ability分为两种类型：Page类型的Ability和Service类型的Ability
Page类型的Ability：带有界面，为用户提供人机交互的能力。
Service类型的Ability：不带界面，为用户提供后台任务机制。
1.2 AbilitySlice
AbilitySlice是单个页面及其控制逻辑的总和，是Page类型Ability特有的组件，一个Page类型的Ability可以包含多个AbilitySlice，此时，这些页面提供的业务能力应当是高度相关的。
1.3 生命周期
生命周期是Ability被调度到启动、激活、隐藏和退出等各个状态的的统称。
Ability生命周期各状态解析：
UNINITIALIZED：未初始状态，为临时状态，Ability被创建后会由UNINITIALIZED状态进入INITIAL状态；
INITIAL：初始化状态，也表示停止状态，表示当前Ability未运行，调用Start后进入INACTIVE，同时回调开发者的OnStart生命周期回调；
INACTIVE：未激活状态，表示当前窗口已显示但是无焦点状态，由于Window暂未支持焦点的概念，当前状态与ACTIVE一致。
ACTIVE：前台激活状态，表示当前窗口已显示，并获取焦点，Ability在退到后台之前先由ACTIVE状态进入INACTIVE状态；
BACKGROUND: 后台状态，表示当前Ability退到后台，Ability在被销毁后由BACKGROUND状态进入INITIAL状态，或者重新被激活后由BACKGROUND状态进入ACTIVE状态。
1.4 AbilityLoader
AbilityLoader负责注册和加载开发者Ability的模块。开发者开发的Ability先要调用AbilityLoader的注册接口注册到框架中，接着Ability启动时会被实例化。
1.5 AbilityManager
AbilityManager负责AbilityKit和Ability管理服务进行IPC的通信。
1.6 EventHandler
EventHandler是AbilityKit提供给开发者的用于在Ability中实现线程间通信的一个模块。
1.7 Ability运行管理服务
Ability运行管理服务是用于协调各Ability运行关系、及生命周期进行调度的系统服务。
其中，服务启动模块负责Ability管理服务的启动、注册等。
服务接口管理模块负责Ability管理服务对外能力的管理。
进程管理模块负责Ability应用所在进程的启动和销毁、及其进程信息维护等功能。Ability栈管理模块负责维护各个Ability之间跳转的先后关系。
生命周期调度模块是Ability管理服务根据系统当前的操作调度Ability进入相应的状态的模块。
连接管理模块是Ability管理服务对Service类型Ability连接管理的模块。
1.8 AppSpawn
AppSpawn是负责创建Ability应用所在进程的系统服务，该服务有较高的权限，为Ability应用设置相应的权限，并预加载一些通用的模块，加速应用的启动。
2. 包管理子系统
包管理子系统，是OpenHarmony为开发者提供的安装包管理框架。
BundleKit：是包管理服务对外提供的接口，有安装/卸载接口、包信息查询接口、包状态变化监听接口。
包扫描器：用来解析本地预制或者安装的安装包，提取里面的各种信息，供管理子模块进行管理，持久化。
包安装子模块：安装，卸载，升级一个包；包安装服务一个单独进程的用于创建删除安装目录，具有较高的权限。
包管理子模块：管理安装包相关的信息，存储持久化包信息。
包安全管理子模块：签名检查、权限授予、权限管理。
HDF驱动LED（可选）
之前在内核中已经注册过一个led_driver驱动，并以led_service服务发布，这一节稍微重构一下代码，功能上没有变化，我们快速过一遍，熟悉HDF的可以自行跳过。
1. 业务代码
先新建头文件vendor\huawei\hdf\led\include\led_ctrl.h。
#ifndef _LED_CTRL_H
#define _LED_CTRL_H
#include "hdf_device_desc.h"
#include "hdf_log.h"
#include "device_resource_if.h"
#include "osal_io.h"
#include "osal_mem.h"
#include "gpio_if.h"
#include "osal_irq.h"
#include "osal_time.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
extern int32_t CtlLED(int mode);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _LED_CTRL_H */再新建源文件 vendor\huawei\hdf\led\led_ctrl.c
#include "led_ctrl.h"
#define HDF_LOG_TAG led_driver // 打印日志所包含的标签，如果不定义则用默认定义的HDF_TAG标签
int32_t CtlLED(int mode)
{
int32_t ret;
uint16_t valRead;
/* LED的GPIO管脚号 */
// uint16_t gpio = 5 * 8 + 1; // 红外补光灯
uint16_t gpio = 2 * 8 + 3; // 绿色指示灯
// uint16_t gpio = 3 * 8 + 4; // 红色指示灯
/* 将GPIO管脚配置为输出 */
ret = GpioSetDir(gpio, GPIO_DIR_OUT);
if (ret != 0)
{
HDF_LOGE("GpioSerDir: failed, ret %d\n", ret);
return ret;
}
if (mode == -1)
{
// 翻转输出口
(void)GpioRead(gpio, &valRead);
ret = GpioWrite(gpio, (valRead == GPIO_VAL_LOW) ? GPIO_VAL_HIGH : GPIO_VAL_LOW);
}
else
{
ret = GpioWrite(gpio, mode);
}
if (ret != 0)
{
HDF_LOGE("GpioWrite: failed, ret %d\n", ret);
return ret;
}
return ret;
}先完成对绿色指示灯的控制逻辑。
2. 驱动实现
在 huawei/hdf 目录下新建一个文件夹 led， 然后在其中新建一个源文件 led.c。
#include "hdf_device_desc.h" // HDF框架对驱动开放相关能力接口的头文件
#include "hdf_log.h" // HDF 框架提供的日志接口头文件
#include "led_ctrl.h"
// #define HDF_LOG_TAG led_driver // 打印日志所包含的标签，如果不定义则用默认定义的HDF_TAG标签
#define LED_WRITE_READ 1 // 读写操作码1
// Dispatch是用来处理用户态发下来的消息
int32_t LedDriverDispatch(struct HdfDeviceIoClient *client, int cmdCode, struct HdfSBuf *data, struct HdfSBuf *reply)
{
int32_t result = HDF_FAILURE;
HDF_LOGE("Led driver dispatch");
if (client == NULL || client->device == NULL)
{
HDF_LOGE("Led driver device is NULL");
return HDF_ERR_INVALID_OBJECT;
}
switch (cmdCode)
{
case LED_WRITE_READ:
const char *recv = HdfSbufReadString(data);
if (recv != NULL)
{
HDF_LOGI("recv: %s", recv);
result = CtlLED(-1);
// result = CtlLED(GPIO_VAL_HIGH);
if (!HdfSbufWriteInt32(reply, result))
{
HDF_LOGE("replay is fail");
}
return HdfDeviceSendEvent(client->device, cmdCode, data);
}
break;
default:
break;
}
return result;
}
//驱动对外提供的服务能力，将相关的服务接口绑定到HDF框架
int32_t HdfLedDriverBind(struct HdfDeviceObject *deviceObject)
{
if (deviceObject == NULL)
{
HDF_LOGE("Led driver bind failed!");
return HDF_ERR_INVALID_OBJECT;
}
static struct IDeviceIoService ledDriver = {
.Dispatch = LedDriverDispatch,
};
deviceObject->service = (struct IDeviceIoService *)(&ledDriver);
HDF_LOGD("Led driver bind success");
return HDF_SUCCESS;
}
// 驱动自身业务初始的接口
int32_t HdfLedDriverInit(struct HdfDeviceObject *deviceObject)
{
if (deviceObject == NULL)
{
HDF_LOGE("Led driver Init failed!");
return HDF_ERR_INVALID_OBJECT;
}
HDF_LOGD("Led driver Init success");
return HDF_SUCCESS;
}
// 驱动资源释放的接口
void HdfLedDriverRelease(struct HdfDeviceObject *deviceObject)
{
if (deviceObject == NULL)
{
HDF_LOGE("Led driver release failed!");
return;
}
HDF_LOGD("Led driver release success");
return;
}
// 定义驱动入口的对象，必须为HdfDriverEntry（在hdf_device_desc.h中定义）类型的全局变量
struct HdfDriverEntry g_ledDriverEntry = {
.moduleVersion = 1,
.moduleName = "led_driver",
.Bind = HdfLedDriverBind,
.Init = HdfLedDriverInit,
.Release = HdfLedDriverRelease,
};
// 调用HDF_INIT将驱动入口注册到HDF框架中，在加载驱动时HDF框架会先调用Bind函数,再调用Init函数加载该驱动，当Init调用异常时，HDF框架会调用Release释放驱动资源并退出。
HDF_INIT(g_ledDriverEntry);
3. 驱动编译
在 huawei/hdf/led 目录下新建编译文件 Makefile。
include $(LITEOSTOPDIR)/../../drivers/hdf/lite/lite.mk
MODULE_NAME := hdf_led_driver
LOCAL_SRCS += led_ctrl.c \
led.c \
LOCAL_INCLUDE := ./include
LOCAL_CFLAGS += -fstack-protector-strong -Wextra -Wall -Werror
include $(HDF_DRIVER)4. 编译结果链接到内核镜像
修改 huawei/hdf/hdf_vendor.mk 文件，添加以下代码
LITEOS_BASELIB += -lhdf_led_driver #链接生成的静态库
LIB_SUBDIRS += $(VENDOR_HDF_DRIVERS_ROOT)/led #驱动代码Makefile的目录5. 驱动配置
修改 vendor/hisi/hi35xx/hi3516dv300/config/device_info/device_info.hcs配置文件，添加驱动的设备描述。
platform :: host {
hostName = "platform_host"; // host名称，host节点是用来存放某一类驱动的容器
priority = 50; // host启动优先级（0-200），值越大优先级越低，建议默认配100，优先级相同则不保证host的加载顺序
device_led :: device { // led设备节点
device0 :: deviceNode { // led驱动的DeviceNode节点
policy = 2; // policy字段是驱动服务发布的策略，在驱动服务管理章节有详细介绍
priority = 100; // 驱动启动优先级（0-200），值越大优先级越低，建议默认配100，优先级相同则不保证device的加载顺序
preload = 0; // 驱动按需加载字段
permission = 0666; // 驱动创建设备节点权限
moduleName = "led_driver"; // 驱动名称，该字段的值必须和驱动入口结构的moduleName值一致
serviceName = "led_service"; // 驱动对外发布服务的名称，必须唯一
deviceMatchAttr = "led_config"; // 驱动私有数据匹配的关键字，必须和驱动私有数据配置表中的match_attr值相等
}
}
编译用户程序框架子系统
1. 添加配置文件
在 build/lite/platform/hi3516dv300_liteos_a/platform.json中的subsystems字段下面添加appexecfwk和aafwk。
{
"subsystem": "aafwk",
"components": [
{
"component": "ability",
"optional": "true",
"dirs": [
"foundation/aafwk"
],
"targets": [
"//foundation/aafwk/frameworks/ability_lite:aafwk_abilitykit_lite",
"//foundation/aafwk/frameworks/ability_lite:aafwk_abilityMain_lite",
"//foundation/aafwk/frameworks/abilitymgr_lite:aafwk_abilityManager_lite",
"//foundation/aafwk/services/abilitymgr_lite:aafwk_services_lite"
],
"features": [
{"enable_ohos_appexecfwk_feature_ability": "true"}
],
"deps": {
"components": [
"hilog_a",
"bundle_mgr",
"system_ability_manager",
"distributed_schedule",
"graphic",
"utils",
"ipc"
],
"third_party": [
"cjson",
"bounds_checking_function"
]
}
}
]
},
{
"subsystem": "appexecfwk",
"components": [
{
"component": "bundle_mgr",
"optional": "true",
"dirs": [
"foundation/appexecfwk"
],
"targets": [
"//foundation/appexecfwk/services/bundlemgr_lite:appexecfwk_services_lite",
"//foundation/appexecfwk/frameworks/bundle_lite:appexecfwk_kits_lite"
],
"features": [],
"deps": {
"components": [
"iam",
"app_verify",
"hilog_a",
"system_ability_manager",
"global_resource_manager",
"graphic",
"utils"
],
"third_party": [
"cjson",
"zlib"
]
}
}
]
},2. 添加编译文件
新建build\lite\config\subsystem\aafwk\BUILD.gn文件，
import("//build/lite/config/subsystem/lite_subsystem.gni")
lite_subsystem("aafwk") {
subsystem_components = [
"//foundation/aafwk/frameworks/ability_lite:aafwk_abilitykit_lite",
"//foundation/aafwk/frameworks/abilitymgr_lite:aafwk_abilityManager_lite",
"//foundation/aafwk/services/abilitymgr_lite:aafwk_services_lite",
]
}新建/build/lite/config/subsystem/appexecfwk/BUILD.gn文件，
import("//build/lite/config/subsystem/lite_subsystem.gni")
lite_subsystem("appexecfwk") {
subsystem_components = [
"//foundation/appexecfwk/kits/appkit_lite:appexecfwk_kit_lite",
"//foundation/appexecfwk/services/bundlemgr_lite:appexecfwk_services_lite",
]
}3. 运行管理服务
用户程序框架有两个系统服务ability管理服务（abilityms）和（bundlems），两系统服务运行于foundation进程中。
abilityms和bundlems注册到sa_manager中，sa_manager运行于foundation进程中，sa_manager为abilityms和bundlems创建线程运行环境。
在foundation/distributedschedule/services/safwk_lite/BUILD.gn中添加对abilityms和bundlems
deps = [
"...",
]
if (ohos_kernel_type == "liteos_a") {
deps += [
"...",
"//foundation/aafwk/services/abilitymgr_lite:abilityms",
"//foundation/appexecfwk/services/bundlemgr_lite:bundlems",
"...",
]
}
基于AbilityKit开发的Ability
1. 主页面实现
新建源文件applications\sample\camera\myLedApp\src\main_ability.cpp
#include "main_ability.h"
namespace OHOS {
REGISTER_AA(MainAbility)
void MainAbility::OnStart(const Want &want)
{
printf("MainAbility::OnStart\n");
SetMainRoute("MainAbilitySlice");
Ability::OnStart(want);
}
2. 分片页面
2.1 定义控件常量
新建源文件main_ability_slice.cpp， 屏幕大小为960x480
#include "main_ability_slice.h"
#include "ability_manager.h"
#include "components/ui_label.h"
#include "components/ui_label_button.h"
namespace OHOS
{
REGISTER_AS(MainAbilitySlice)
constexpr static int BUTTON1_POSITION_X = 380;
constexpr static int BUTTON1_POSITION_Y = 200;
constexpr static int BUTTON_WIDTH = 200;
constexpr static int BUTTON_HEIGHT = 80;
constexpr static int ROOT_VIEW_POSITION_X = 0;
constexpr static int ROOT_VIEW_POSITION_Y = 0;
constexpr static int ROOT_VIEW_WIDTH = 960;
constexpr static int ROOT_VIEW_HEIGHT = 480;
constexpr static uint8_t ROOT_VIEW_OPACITY = 255;
constexpr static uint8_t FONT_ID = 10;
constexpr static int BUTTON1_POSITION_X = 380;
constexpr static int BUTTON1_POSITION_Y = 200;
constexpr static int BUTTON_WIDTH = 200;
constexpr static int BUTTON_HEIGHT = 80;
constexpr static int ROOT_VIEW_POSITION_X = 0;
constexpr static int ROOT_VIEW_POSITION_Y = 0;
constexpr static int ROOT_VIEW_WIDTH = 960;
constexpr static int ROOT_VIEW_HEIGHT = 480;
constexpr static uint8_t ROOT_VIEW_OPACITY = 255;
constexpr static uint8_t FONT_ID = 10;
} // namespace OHOS
2.2 创建按钮和布局
在生命周期函数OnStart中，全屏放置一个rootView_，居中位置放置一个按钮button1。
void MainAbilitySlice::OnStart(const Want &want)
{
printf("MainAbilitySlice::OnStart\n");
AbilitySlice::OnStart(want);
auto button1 = new UILabelButton();
button1->SetPosition(BUTTON1_POSITION_X, BUTTON1_POSITION_Y);
button1->SetText("翻转 LED");
button1->Resize(BUTTON_WIDTH, BUTTON_HEIGHT);
button1->SetFontId(FONT_ID);
button1->SetStyle(STYLE_TEXT_COLOR, Color::Black().full);
button1->SetStyle(STYLE_TEXT_OPA, ROOT_VIEW_OPACITY);
button1->SetStyle(STYLE_BACKGROUND_OPA, ROOT_VIEW_OPACITY);
rootView_ = RootView::GetWindowRootView();
rootView_->SetPosition(ROOT_VIEW_POSITION_X, ROOT_VIEW_POSITION_Y);
rootView_->Resize(ROOT_VIEW_WIDTH, ROOT_VIEW_HEIGHT);
rootView_->Add(button1);
SetUIContent(rootView_);
}
2.3 实现驱动消息机制
这里顺便提一下，文档中DevSvcManagerClntGetService接口仅在内核态有效，可以方便的获取服务并直接调用。鸿蒙作为微内核的OS，想从用户态调用内核态函数，要么用框架的消息机制，要么自己用中断服务实现。
#define LED_WRITE_READ 1
#define LED_SERVICE "led_service"
static int OnDevEventReceived(void *priv, uint32_t id, struct HdfSBuf *data)
{
const char *string = HdfSbufReadString(data);
if (string == NULL)
{
printf("fail to read string in event data\n");
return HDF_FAILURE;
}
printf("%s: dev event received: %u %s\n", (char *)priv, id, string);
return HDF_SUCCESS;
}
static int SendEvent(struct HdfIoService *serv, const char *eventData)
{
int ret = 0;
struct HdfSBuf *data = HdfSBufObtainDefaultSize();
if (data == NULL)
{
printf("fail to obtain sbuf data\n");
return 1;
}
struct HdfSBuf *reply = HdfSBufObtainDefaultSize();
if (reply == NULL)
{
printf("fail to obtain sbuf reply\n");
ret = HDF_DEV_ERR_NO_MEMORY;
HdfSBufRecycle(data);
return ret;
}
if (!HdfSbufWriteString(data, eventData))
{
printf("fail to write sbuf\n");
ret = HDF_FAILURE;
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
ret = serv->dispatcher->Dispatch(&serv->object, LED_WRITE_READ, data, reply);
if (ret != HDF_SUCCESS)
{
printf("fail to send service call\n");
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
int replyData = 0;
if (!HdfSbufReadInt32(reply, &replyData))
{
printf("fail to get service call reply\n");
ret = HDF_ERR_INVALID_OBJECT;
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
printf("Get reply is: %d\n", replyData);
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
2.4 加入点击事件
每次点击按钮，向内核态发送一次消息。
auto onClick = [this](UIView &view, const Event &event) -> bool {
printf("led button pressed\n");
struct HdfIoService *serv = HdfIoServiceBind(LED_SERVICE, 0);
if (serv == NULL)
{
printf("fail to get service %s\n", LED_SERVICE);
return false;
}
static struct HdfDevEventlistener listener = {
.callBack = OnDevEventReceived,
.priv = (void *)"Service0"};
if (HdfDeviceRegisterEventListener(serv, &listener) != HDF_SUCCESS)
{
printf("fail to register event listener\n");
return false;
}
const char *send_cmd = "toggle LED";
if (SendEvent(serv, send_cmd))
{
printf("fail to send event\n");
return false;
}
if (HdfDeviceUnregisterEventListener(serv, &listener))
{
printf("fail to unregister listener\n");
return false;
}
HdfIoServiceRecycle(serv);
return true;
};
2.5 注销页面
在生命周期函数OnStop中，删除所有节点，回收系统资源。
void DeleteViewChildren(UIView *view)
{
if (view == nullptr) {
return;
}
while (view != nullptr) {
UIView *tempView = view;
view = view->GetNextSibling();
if (tempView->IsViewGroup()) {
DeleteViewChildren(dynamic_cast<UIViewGroup *>(tempView)->GetChildrenHead());
}
if (tempView->GetParent()) {
dynamic_cast<UIViewGroup *>(tempView->GetParent())->Remove(tempView);
}
delete tempView;
}
}
void MainAbilitySlice::OnStop()
{
printf("MainAbilitySlice::OnStop\n");
AbilitySlice::OnStop();
DeleteViewChildren(rootView_);
}3. 编译配置
新增 applications\sample\camera\myLedApp\BUILD.gn文件
import("//build/lite/config/component/lite_component.gni")
import("//build/lite/config/subsystem/aafwk/config.gni")
HDF_FRAMEWORKS = "//drivers/hdf/frameworks"
src_path = "//applications/sample/camera/myLedApp/src"
lite_library("ledability") {
target_type = "shared_library"
ldflags = [
"-shared",
]
sources = [
"${src_path}/main_ability.cpp",
"${src_path}/main_ability_slice.cpp",
]
include_dirs = [
".",
"//foundation/aafwk/frameworks/ability_lite/example/entry/src/main/cpp",
"//foundation/aafwk/interfaces/innerkits/abilitymgr_lite",
"//foundation/aafwk/interfaces/kits/ability_lite",
"//foundation/aafwk/interfaces/kits/want_lite",
"//foundation/appexecfwk/interfaces/kits/bundle_lite",
"//foundation/appexecfwk/utils/bundle_lite",
"//foundation/communication/interfaces/kits/ipc_lite",
"//foundation/graphic/lite/interfaces/kits/config",
"//foundation/graphic/lite/interfaces/kits/ui",
"//foundation/graphic/lite/interfaces/kits/utils",
"//kernel/liteos_a/kernel/common",
"//kernel/liteos_a/kernel/include",
"//drivers/hdf/lite/include/host",
"$HDF_FRAMEWORKS/ability/sbuf/include",
"$HDF_FRAMEWORKS/core/shared/include",
"$HDF_FRAMEWORKS/core/host/include",
"$HDF_FRAMEWORKS/core/master/include",
"$HDF_FRAMEWORKS/include/core",
"$HDF_FRAMEWORKS/include/utils",
"$HDF_FRAMEWORKS/utils/include",
"$HDF_FRAMEWORKS/include/osal",
"//kernel/liteos_a/platform/include",
"$HDF_FRAMEWORKS/adapter/syscall/include",
"$HDF_FRAMEWORKS/adapter/vnode/include",
]
deps = [
"//foundation/aafwk/frameworks/ability_lite:aafwk_abilitykit_lite",
"//drivers/hdf/lite/manager:hdf_core",
"//drivers/hdf/lite/adapter/osal/posix:hdf_posix_osal",
]
defines = [
"OHOS_APPEXECFWK_BMS_BUNDLEMANAGER",
]
if (enable_ohos_appexecfwk_feature_ability == true) {
deps += [
"//foundation/graphic/lite/frameworks/ui:ui",
]
defines += [
"ENABLE_WINDOW=1",
"ABILITY_WINDOW_SUPPORT"
]
}
output_dir = "$root_out_dir/dev_tools/led"
}4. 应用配置文件
新建 applications\sample\camera\myLedApp\config.json
{
"app": {
"bundleName": "com.bluishfish.ledability",
"vendor": "huawei",
"version": {
"code": 1,
"name": "1.0"
},
"apiVersion": {
"compatible": 3,
"target": 3
}
},
"deviceConfig": {
"default": {
"keepAlive": false
}
},
"module": {
"deviceType": [
"smartVision"
],
"distro": {
"deliveryWithInstall": true,
"moduleName": "ledability",
"moduleType": "entry"
},
"abilities": [{
"name": "MainAbility",
"icon": "assets/entry/resources/base/media/icon.png",
"label": "Led Ability",
"launchType": "standard",
"type": "page",
"visible": true
}
]
}
}
5. 板级编译配置
复制 build/lite/product/ipcamera_hi3516dv300.json，改名为my_hi3516dv300在子系统里加入
{
"ohos_version": "OpenHarmony 1.0",
"board": "hi3516dv300",
"kernel": "liteos_a",
"compiler": "clang",
"subsystem": [
{
"name": "aafwk",
"component": [
"......",
{ "name": "ability_led", "dir": "//applications/sample/camera/myLedApp:ledability", "features": []}
]
"......"6. 编译应用
python build.py my_hi3516dv300 -b debug
将系统烧录到开发板上。
7. 打包应用
在 assets\entry\resources\base\media\目录下放置一个icon.png作为启动图标。
将applications\sample\camera\myLedApp\config.json和 Z:\openharmony\out\my_hi3516dv300\dev_tools\led\libledability.so打包压缩成zip包
改名为ledability.hap ，复制到NFS共享目录
8. 安装Hap
mkdir nfs
mount 192.168.1.57:/nfs /nfs nfs
./nfs/dev_tools/bin/bm set -s disable
./nfs/dev_tools/bin/bm install -p ./nfs/ledability.hap
9. 运行程序
./nfs/dev_tools/bin/aa start -p com.bluishfish.ledability -n MainAbility
完美！
总结
整理一下思路，
我们先用AbilityKit绘制Ability页面，在其button1上绑定一个按钮事件；
触发后，由用户子系统寻找到led_server服务，向HDF框架发送消息；
内核驱动led_driver接收到消息后，调用底层GPIO控制LED翻转，并将操作状态以reply消息的形式传回用户侧；
后续可以接着根据返回状态更新下界面。
好了，在此基础上美化下界面，接个继电器做个智能家居的App应该不是难事了。
源码下载
PS：最近收到了社区之星的礼物，还有前沿新书《鸿蒙应用开发实战》，感谢一下小编的辛苦工作。
下一篇预告
用C++来写UI开发效率总是不如java和js高的，
何况还没法用上DevEco Studio辅助设计，
下一篇我们尝试实现更多的设备能力，
并用JS框架来访问内核层，
敬请期待...
图片好像挂了，方便楼主补一下吗？
楼主...有两张图片看不到呀╯︿╰
好像已经修复了，感谢小编。
看到礼物收到了，也就放心了！