這一篇我們繼續(xù)深入一點(diǎn)點(diǎn)，嘗試打通從用戶態(tài)UI到內(nèi)核態(tài)HDF之間的聯(lián)系。其中涉及到的調(diào)用關(guān)系比較復(fù)雜，建議在“用鴻蒙開發(fā)AI應(yīng)用（五）HDF 驅(qū)動(dòng)補(bǔ)光燈”的基礎(chǔ)上閱讀本文，HDF的相關(guān)細(xì)節(jié)這里就不在贅述了。

背景知識(shí)
用戶程序框架子系統(tǒng)包含兩個(gè)大的模塊：Ability子系統(tǒng)和包管理子系統(tǒng)。

1. Ability子系統(tǒng)

1.1 Ability
Ability是系統(tǒng)調(diào)度應(yīng)用的最小單元，是能夠完成一個(gè)獨(dú)立功能的組件，一個(gè)應(yīng)用可以包含一個(gè)或多個(gè)Ability。Ability分為兩種類型：Page類型的Ability和Service類型的Ability

Page類型的Ability：帶有界面，為用戶提供人機(jī)交互的能力。
Service類型的Ability：不帶界面，為用戶提供后臺(tái)任務(wù)機(jī)制。
1.2 AbilitySlice
AbilitySlice是單個(gè)頁面及其控制邏輯的總和，是Page類型Ability特有的組件，一個(gè)Page類型的Ability可以包含多個(gè)AbilitySlice，此時(shí)，這些頁面提供的業(yè)務(wù)能力應(yīng)當(dāng)是高度相關(guān)的。

1.3 生命周期
生命周期是Ability被調(diào)度到啟動(dòng)、激活、隱藏和退出等各個(gè)狀態(tài)的的統(tǒng)稱。

Ability生命周期各狀態(tài)解析：

UNINITIALIZED：未初始狀態(tài)，為臨時(shí)狀態(tài)，Ability被創(chuàng)建后會(huì)由UNINITIALIZED狀態(tài)進(jìn)入INITIAL狀態(tài)；
INITIAL：初始化狀態(tài)，也表示停止?fàn)顟B(tài)，表示當(dāng)前Ability未運(yùn)行，調(diào)用Start后進(jìn)入INACTIVE，同時(shí)回調(diào)開發(fā)者的OnStart生命周期回調(diào)；
INACTIVE：未激活狀態(tài)，表示當(dāng)前窗口已顯示但是無焦點(diǎn)狀態(tài)，由于Window暫未支持焦點(diǎn)的概念，當(dāng)前狀態(tài)與ACTIVE一致。
ACTIVE：前臺(tái)激活狀態(tài)，表示當(dāng)前窗口已顯示，并獲取焦點(diǎn)，Ability在退到后臺(tái)之前先由ACTIVE狀態(tài)進(jìn)入INACTIVE狀態(tài)；
BACKGROUND: 后臺(tái)狀態(tài)，表示當(dāng)前Ability退到后臺(tái)，Ability在被銷毀后由BACKGROUND狀態(tài)進(jìn)入INITIAL狀態(tài)，或者重新被激活后由BACKGROUND狀態(tài)進(jìn)入ACTIVE狀態(tài)。
1.4 AbilityLoader
AbilityLoader負(fù)責(zé)注冊和加載開發(fā)者Ability的模塊。開發(fā)者開發(fā)的Ability先要調(diào)用AbilityLoader的注冊接口注冊到框架中，接著Ability啟動(dòng)時(shí)會(huì)被實(shí)例化。

1.5 AbilityManager
AbilityManager負(fù)責(zé)AbilityKit和Ability管理服務(wù)進(jìn)行IPC的通信。

1.6 EventHandler
EventHandler是AbilityKit提供給開發(fā)者的用于在Ability中實(shí)現(xiàn)線程間通信的一個(gè)模塊。

1.7 Ability運(yùn)行管理服務(wù)
Ability運(yùn)行管理服務(wù)是用于協(xié)調(diào)各Ability運(yùn)行關(guān)系、及生命周期進(jìn)行調(diào)度的系統(tǒng)服務(wù)。

其中，服務(wù)啟動(dòng)模塊負(fù)責(zé)Ability管理服務(wù)的啟動(dòng)、注冊等。

服務(wù)接口管理模塊負(fù)責(zé)Ability管理服務(wù)對外能力的管理。

進(jìn)程管理模塊負(fù)責(zé)Ability應(yīng)用所在進(jìn)程的啟動(dòng)和銷毀、及其進(jìn)程信息維護(hù)等功能。Ability棧管理模塊負(fù)責(zé)維護(hù)各個(gè)Ability之間跳轉(zhuǎn)的先后關(guān)系。

生命周期調(diào)度模塊是Ability管理服務(wù)根據(jù)系統(tǒng)當(dāng)前的操作調(diào)度Ability進(jìn)入相應(yīng)的狀態(tài)的模塊。

連接管理模塊是Ability管理服務(wù)對Service類型Ability連接管理的模塊。

1.8 AppSpawn
AppSpawn是負(fù)責(zé)創(chuàng)建Ability應(yīng)用所在進(jìn)程的系統(tǒng)服務(wù)，該服務(wù)有較高的權(quán)限，為Ability應(yīng)用設(shè)置相應(yīng)的權(quán)限，并預(yù)加載一些通用的模塊，加速應(yīng)用的啟動(dòng)。

2. 包管理子系統(tǒng)
包管理子系統(tǒng)，是OpenHarmony為開發(fā)者提供的安裝包管理框架。

BundleKit：是包管理服務(wù)對外提供的接口，有安裝/卸載接口、包信息查詢接口、包狀態(tài)變化監(jiān)聽接口。
包掃描器：用來解析本地預(yù)制或者安裝的安裝包，提取里面的各種信息，供管理子模塊進(jìn)行管理，持久化。
包安裝子模塊：安裝，卸載，升級(jí)一個(gè)包；包安裝服務(wù)一個(gè)單獨(dú)進(jìn)程的用于創(chuàng)建刪除安裝目錄，具有較高的權(quán)限。
包管理子模塊：管理安裝包相關(guān)的信息，存儲(chǔ)持久化包信息。
包安全管理子模塊：簽名檢查、權(quán)限授予、權(quán)限管理。

HDF驅(qū)動(dòng)LED（可選）
之前在內(nèi)核中已經(jīng)注冊過一個(gè)led_driver驅(qū)動(dòng)，并以led_service服務(wù)發(fā)布，這一節(jié)稍微重構(gòu)一下代碼，功能上沒有變化，我們快速過一遍，熟悉HDF的可以自行跳過。

1. 業(yè)務(wù)代碼
先新建頭文件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 // 打印日志所包含的標(biāo)簽，如果不定義則用默認(rèn)定義的HDF_TAG標(biāo)簽

int32_t CtlLED(int mode)
{
    int32_t ret;
    uint16_t valRead;
    /* LED的GPIO管腳號(hào) */
    // uint16_t gpio = 5 * 8 + 1;  // 紅外補(bǔ)光燈
    uint16_t gpio = 2 * 8 + 3;  // 綠色指示燈
    // uint16_t gpio = 3 * 8 + 4;  // 紅色指示燈

    /* 將GPIO管腳配置為輸出 */
    ret = GpioSetDir(gpio, GPIO_DIR_OUT);
    if (ret != 0)
    {
        HDF_LOGE("GpioSerDir: failed, ret %d
", ret);
        return ret;
    }

    if (mode == -1)
    {
        // 翻轉(zhuǎn)輸出口
        (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
", ret);
        return ret;
    }
    return ret;
}

先完成對綠色指示燈的控制邏輯。

2. 驅(qū)動(dòng)實(shí)現(xiàn) 在 huawei/hdf 目錄下新建一個(gè)文件夾 led， 然后在其中新建一個(gè)源文件 led.c。

#include "hdf_device_desc.h" // HDF框架對驅(qū)動(dòng)開放相關(guān)能力接口的頭文件
#include "hdf_log.h"         // HDF 框架提供的日志接口頭文件
#include "led_ctrl.h"

// #define HDF_LOG_TAG led_driver // 打印日志所包含的標(biāo)簽，如果不定義則用默認(rèn)定義的HDF_TAG標(biāo)簽
#define LED_WRITE_READ 1       // 讀寫操作碼1

// Dispatch是用來處理用戶態(tài)發(fā)下來的消息
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;
}

//驅(qū)動(dòng)對外提供的服務(wù)能力，將相關(guān)的服務(wù)接口綁定到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;
}


// 驅(qū)動(dòng)自身業(yè)務(wù)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;
}

// 驅(qū)動(dòng)資源釋放的接口
void HdfLedDriverRelease(struct HdfDeviceObject *deviceObject)
{
    if (deviceObject == NULL)
    {
        HDF_LOGE("Led driver release failed!");
        return;
    }

    HDF_LOGD("Led driver release success");
    return;
}

// 定義驅(qū)動(dòng)入口的對象，必須為HdfDriverEntry（在hdf_device_desc.h中定義）類型的全局變量
struct HdfDriverEntry g_ledDriverEntry = {
    .moduleVersion = 1,
    .moduleName = "led_driver",
    .Bind = HdfLedDriverBind,
    .Init = HdfLedDriverInit,
    .Release = HdfLedDriverRelease,
};

// 調(diào)用HDF_INIT將驅(qū)動(dòng)入口注冊到HDF框架中，在加載驅(qū)動(dòng)時(shí)HDF框架會(huì)先調(diào)用Bind函數(shù),再調(diào)用Init函數(shù)加載該驅(qū)動(dòng)，當(dāng)Init調(diào)用異常時(shí)，HDF框架會(huì)調(diào)用Release釋放驅(qū)動(dòng)資源并退出。
HDF_INIT(g_ledDriverEntry);

3. 驅(qū)動(dòng)編譯 在 huawei/hdf/led 目錄下新建編譯文件 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. 編譯結(jié)果鏈接到內(nèi)核鏡像 修改 huawei/hdf/hdf_vendor.mk 文件，添加以下代碼

LITEOS_BASELIB += -lhdf_led_driver  #鏈接生成的靜態(tài)庫
LIB_SUBDIRS    += $(VENDOR_HDF_DRIVERS_ROOT)/led  #驅(qū)動(dòng)代碼Makefile的目錄

5. 驅(qū)動(dòng)配置 修改 vendor/hisi/hi35xx/hi3516dv300/config/device_info/device_info.hcs配置文件，添加驅(qū)動(dòng)的設(shè)備描述。

platform :: host {
    hostName = "platform_host";  // host名稱，host節(jié)點(diǎn)是用來存放某一類驅(qū)動(dòng)的容器
    priority = 50;  // host啟動(dòng)優(yōu)先級(jí)（0-200），值越大優(yōu)先級(jí)越低，建議默認(rèn)配100，優(yōu)先級(jí)相同則不保證host的加載順序

    device_led :: device {                  // led設(shè)備節(jié)點(diǎn)
        device0 :: deviceNode {             // led驅(qū)動(dòng)的DeviceNode節(jié)點(diǎn)
            policy = 2;                     // policy字段是驅(qū)動(dòng)服務(wù)發(fā)布的策略，在驅(qū)動(dòng)服務(wù)管理章節(jié)有詳細(xì)介紹
            priority = 100;                 // 驅(qū)動(dòng)啟動(dòng)優(yōu)先級(jí)（0-200），值越大優(yōu)先級(jí)越低，建議默認(rèn)配100，優(yōu)先級(jí)相同則不保證device的加載順序
            preload = 0;                    // 驅(qū)動(dòng)按需加載字段
            permission = 0666;              // 驅(qū)動(dòng)創(chuàng)建設(shè)備節(jié)點(diǎn)權(quán)限
            moduleName = "led_driver";      // 驅(qū)動(dòng)名稱，該字段的值必須和驅(qū)動(dòng)入口結(jié)構(gòu)的moduleName值一致
            serviceName = "led_service";    // 驅(qū)動(dòng)對外發(fā)布服務(wù)的名稱，必須唯一
            deviceMatchAttr = "led_config"; // 驅(qū)動(dòng)私有數(shù)據(jù)匹配的關(guān)鍵字，必須和驅(qū)動(dòng)私有數(shù)據(jù)配置表中的match_attr值相等
        }
    } 

編譯用戶程序框架子系統(tǒng) 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": [
        "http://foundation/aafwk/frameworks/ability_lite:aafwk_abilitykit_lite",
        "http://foundation/aafwk/frameworks/ability_lite:aafwk_abilityMain_lite",
        "http://foundation/aafwk/frameworks/abilitymgr_lite:aafwk_abilityManager_lite",
        "http://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": [
        "http://foundation/appexecfwk/services/bundlemgr_lite:appexecfwk_services_lite",
        "http://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. 添加編譯文件 新建buildliteconfigsubsystemaafwkBUILD.gn文件，

import("http://build/lite/config/subsystem/lite_subsystem.gni")

lite_subsystem("aafwk") {
    subsystem_components = [
        "http://foundation/aafwk/frameworks/ability_lite:aafwk_abilitykit_lite",
        "http://foundation/aafwk/frameworks/abilitymgr_lite:aafwk_abilityManager_lite",
        "http://foundation/aafwk/services/abilitymgr_lite:aafwk_services_lite",
    ]
}

新建/build/lite/config/subsystem/appexecfwk/BUILD.gn文件，

import("http://build/lite/config/subsystem/lite_subsystem.gni")

lite_subsystem("appexecfwk") {
    subsystem_components = [
        "http://foundation/appexecfwk/kits/appkit_lite:appexecfwk_kit_lite",
        "http://foundation/appexecfwk/services/bundlemgr_lite:appexecfwk_services_lite",
    ]
}

3. 運(yùn)行管理服務(wù) 用戶程序框架有兩個(gè)系統(tǒng)服務(wù)ability管理服務(wù)（abilityms）和（bundlems），兩系統(tǒng)服務(wù)運(yùn)行于foundation進(jìn)程中。

abilityms和bundlems注冊到sa_manager中，sa_manager運(yùn)行于foundation進(jìn)程中，sa_manager為abilityms和bundlems創(chuàng)建線程運(yùn)行環(huán)境。

在foundation/distributedschedule/services/safwk_lite/BUILD.gn中添加對abilityms和bundlems

deps = [
    "...",
]
if (ohos_kernel_type == "liteos_a") {
    deps += [
        "...",
        "http://foundation/aafwk/services/abilitymgr_lite:abilityms",
        "http://foundation/appexecfwk/services/bundlemgr_lite:bundlems",
        "...",
    ]
}

基于AbilityKit開發(fā)的Ability 1. 主頁面實(shí)現(xiàn) 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::OnStart
");
    SetMainRoute("MainAbilitySlice");

    Ability::OnStart(want);
}

2. 分片頁面 2.1 定義控件常量 新建源文件main_ability_slice.cpp， 屏幕大小為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 創(chuàng)建按鈕和布局 在生命周期函數(shù)OnStart中，全屏放置一個(gè)rootView_，居中位置放置一個(gè)按鈕button1。

void MainAbilitySlice::OnStart(const Want &want)
{
    printf("MainAbilitySlice::OnStart
");
    AbilitySlice::OnStart(want);
	
	auto button1 = new UILabelButton();
    button1->SetPosition(BUTTON1_POSITION_X, BUTTON1_POSITION_Y);
    button1->SetText("翻轉(zhuǎn) 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 實(shí)現(xiàn)驅(qū)動(dòng)消息機(jī)制 這里順便提一下，文檔中DevSvcManagerClntGetService接口僅在內(nèi)核態(tài)有效，可以方便的獲取服務(wù)并直接調(diào)用。鴻蒙作為微內(nèi)核的OS，想從用戶態(tài)調(diào)用內(nèi)核態(tài)函數(shù)，要么用框架的消息機(jī)制，要么自己用中斷服務(wù)實(shí)現(xiàn)。

#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
");
        return HDF_FAILURE;
    }
    printf("%s: dev event received: %u %s
", (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
");
        return 1;
    }

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

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

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

    HdfSBufRecycle(data);
    HdfSBufRecycle(reply);
    return ret;
}

2.4 加入點(diǎn)擊事件 每次點(diǎn)擊按鈕，向內(nèi)核態(tài)發(fā)送一次消息。

auto onClick = [this](UIView &view, const Event &event) -> bool {
    printf("led button pressed
");

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

    const char *send_cmd = "toggle LED";

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

    if (HdfDeviceUnregisterEventListener(serv, &listener))
    {
        printf("fail to  unregister listener
");
        return false;
    }

    HdfIoServiceRecycle(serv);

    return true;
};

2.5 注銷頁面 在生命周期函數(shù)OnStop中，刪除所有節(jié)點(diǎn)，回收系統(tǒng)資源。

void DeleteViewChildren(UIView *view)
{
    if (view == nullptr) {
        return;
    }
    while (view != nullptr) {
        UIView *tempView = view;
        view = view->GetNextSibling();
        if (tempView->IsViewGroup()) {
            DeleteViewChildren(dynamic_cast(tempView)->GetChildrenHead());
        }
        if (tempView->GetParent()) {
            dynamic_cast(tempView->GetParent())->Remove(tempView);
        }
        delete tempView;
    }
}

void MainAbilitySlice::OnStop()
{
    printf("MainAbilitySlice::OnStop
");
    AbilitySlice::OnStop();
    DeleteViewChildren(rootView_);
}

3. 編譯配置 新增 applicationssamplecameramyLedAppBUILD.gn文件

import("http://build/lite/config/component/lite_component.gni")
import("http://build/lite/config/subsystem/aafwk/config.gni")

HDF_FRAMEWORKS = "http://drivers/hdf/frameworks"
src_path = "http://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 = [
        ".",
        "http://foundation/aafwk/frameworks/ability_lite/example/entry/src/main/cpp",
        "http://foundation/aafwk/interfaces/innerkits/abilitymgr_lite",
        "http://foundation/aafwk/interfaces/kits/ability_lite",
        "http://foundation/aafwk/interfaces/kits/want_lite",
        "http://foundation/appexecfwk/interfaces/kits/bundle_lite",
        "http://foundation/appexecfwk/utils/bundle_lite",
        "http://foundation/communication/interfaces/kits/ipc_lite",
        "http://foundation/graphic/lite/interfaces/kits/config",
        "http://foundation/graphic/lite/interfaces/kits/ui",
        "http://foundation/graphic/lite/interfaces/kits/utils",
        "http://kernel/liteos_a/kernel/common",
        "http://kernel/liteos_a/kernel/include",
        "http://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",
        "http://kernel/liteos_a/platform/include",
        "$HDF_FRAMEWORKS/adapter/syscall/include",
        "$HDF_FRAMEWORKS/adapter/vnode/include",
    ]

    deps = [
        "http://foundation/aafwk/frameworks/ability_lite:aafwk_abilitykit_lite",
        "http://drivers/hdf/lite/manager:hdf_core",
        "http://drivers/hdf/lite/adapter/osal/posix:hdf_posix_osal",
    ]

    defines = [
        "OHOS_APPEXECFWK_BMS_BUNDLEMANAGER",
    ]

    if (enable_ohos_appexecfwk_feature_ability == true) {
        deps += [
            "http://foundation/graphic/lite/frameworks/ui:ui",
        ]
        defines += [
            "ENABLE_WINDOW=1",
            "ABILITY_WINDOW_SUPPORT"
        ]
    }
    output_dir = "$root_out_dir/dev_tools/led"
}

4. 應(yīng)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. 板級(jí)編譯配置 復(fù)制 build/lite/product/ipcamera_hi3516dv300.json，改名為my_hi3516dv300在子系統(tǒng)里加入

{
  "ohos_version": "OpenHarmony 1.0",
  "board": "hi3516dv300",
  "kernel": "liteos_a",
  "compiler": "clang",
  "subsystem": [
    {
      "name": "aafwk",
      "component": [
            "......",
            { "name": "ability_led", "dir": "http://applications/sample/camera/myLedApp:ledability", "features": []}
        ]
"......"

6. 編譯應(yīng)用

python build.py my_hi3516dv300 -b debug

將系統(tǒng)燒錄到開發(fā)板上。

7. 打包應(yīng)用 在 assetsentry esourcesasemedia目錄下放置一個(gè)icon.png作為啟動(dòng)圖標(biāo)。

將applicationssamplecameramyLedAppconfig.json和 Z:openharmonyoutmy_hi3516dv300dev_toolsledlibledability.so打包壓縮成zip包

改名為ledability.hap ，復(fù)制到NFS共享目錄

8. 安裝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. 運(yùn)行程序

./nfs/dev_tools/bin/aa start -p com.bluishfish.ledability -n MainAbility

完美！