用鸿蒙开发AI应用（七）触摸屏控制LED - HarmonyOS技术社区 - 电子技术论坛

2021-01-10 09:35:53

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vendorhuaweihdfledincludeled_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 vendorhuaweihdfledled_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 %dn", 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 %dn", 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buildliteconfigsubsystemaafwkBUILD.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Ability1. 主页面实现

新建源文件applicationssamplecameramyLedAppsrcmain_ability.cpp

#include "main_ability.h"

namespace OHOS {
REGISTER_AA(MainAbility)

void MainAbility::OnStart(const Want &want)
{
printf("MainAbility::OnStartn");
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 OHOS2.2 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::OnStartn");
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 datan");
      return HDF_FAILURE;
}
printf("%s: dev event received: %u %sn", (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 ***uf datan");
      return 1;
}

struct HdfSBuf *reply = HdfSBufObtainDefaultSize();
if (reply == NULL)
{
      printf("fail to obtain ***uf replyn");
      ret = HDF_DEV_ERR_NO_MEMORY;
      HdfSBufRecycle(data);
      return ret;
}

if (!HdfSbufWriteString(data, eventData))
{
      printf("fail to write ***ufn");
      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 calln");
      HdfSBufRecycle(data);
      HdfSBufRecycle(reply);
      return ret;
}

int replyData = 0;
if (!HdfSbufReadInt32(reply, &replyData))
{
      printf("fail to get service call replyn");
      ret = HDF_ERR_INVALID_OBJECT;
      HdfSBufRecycle(data);
      HdfSBufRecycle(reply);
      return ret;
}
printf("Get reply is: %dn", 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 pressedn");

struct HdfIoService *serv = HdfIoServiceBind(LED_SERVICE, 0);
if (serv == NULL)
{
      printf("fail to get service %sn", LED_SERVICE);
      return false;
}

static struct HdfDevEventlistener listener = {
      .callBack = OnDevEventReceived,
      .priv = (void *)"Service0"};

if (HdfDeviceRegisterEventListener(serv, &listener) != HDF_SUCCESS)
{
      printf("fail to register event listenern");
      return false;
}

const char *send_cmd = "toggle LED";

if (SendEvent(serv, send_cmd))
{
      printf("fail to send eventn");
      return false;
}

if (HdfDeviceUnregisterEventListener(serv, &listener))
{
      printf("fail to  unregister listenern");
      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::OnStopn");
AbilitySlice::OnStop();
DeleteViewChildren(rootView_);
}3. 编译配置

新增 applicationssamplecameramyLedAppBUILD.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",
      "$HDF_FRAMEWORKS/ability/***uf/include",
      "$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 applicationssamplecameramyLedAppconfig.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