在 HarmonyOS 中如何使用 Native C++

发表于 2024-12-19 分类于 HarmonyOS 阅读次数： Changyan：本文字数： 1.5k 阅读时长 ≈ 6 分钟

环境

工具: HUAWEI DevEco Studio

设备: 支持HarmonyOS NEXT 的设备（真机/模拟器）

创建项目

新建一个项目，选择 [Native C++] 的模版

然后生成一个默认的工程

API 版本 : 5.0.1 (API 13)

分析项目

import { hilog } from '@kit.PerformanceAnalysisKit';
import testNapi from 'libentry.so';

@Entry
@Component
struct Index {
  @State message: string = 'Hello World';

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .onClick(() => {
            hilog.info(0x0000, 'testTag', 'Test NAPI 2 + 3 = %{public}d', testNapi.add(2, 3));
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}

分析这个默认工程，根据index.ets代码显示，是在Native下注册是add的计算方法，通过传入两个参数计算和，文中传入了 2 和 3，当点击界面上的Hello world 文本时调用计算方法，日志输出如下

1	12-19 55333-55333 A00000/com..../testTag com.xw....lication I Test NAPI 2 + 3 = 5

点击16行，testNapi.add() 方法跳过去，在 index.d.ts 中定义了接口方法

1	export const add: (a: number, b: number) => number;

这个 testNapi 又是通过 libentry.so 引入的

1	import testNapi from 'libentry.so';

在 CMakeLists 15行我们可以链接库的地方

接着打开 cpp 目录下的 napi_init.cpp 文件

#include "napi/native_api.h"

static napi_value Add(napi_env env, napi_callback_info info)
{
    size_t argc = 2;
    napi_value args[2] = {nullptr};

    napi_get_cb_info(env, info, &argc, args , nullptr, nullptr);

    napi_valuetype valuetype0;
    napi_typeof(env, args[0], &valuetype0);

    napi_valuetype valuetype1;
    napi_typeof(env, args[1], &valuetype1);

    double value0;
    napi_get_value_double(env, args[0], &value0);

    double value1;
    napi_get_value_double(env, args[1], &value1);

    napi_value sum;
    napi_create_double(env, value0 + value1, &sum);

    return sum;

}

EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports)
{
    napi_property_descriptor desc[] = {
        { "add", nullptr, Add, nullptr, nullptr, nullptr, napi_default, nullptr }
    };
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}
EXTERN_C_END

static napi_module demoModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = ((void*)0),
    .reserved = { 0 },
};

extern "C" __attribute__((constructor)) void RegisterEntryModule(void)
{
    napi_module_register(&demoModule);
}

按照以上的使用流程，接下来实现一个类似的示例

修改项目

以下通过C API 获取设备信息 DeviceInfo

链接

CMakeList.txt

# the minimum version of CMake.
cmake_minimum_required(VERSION 3.5.0)
project(HMBehavior)

set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})

if(DEFINED PACKAGE_FIND_FILE)
    include(${PACKAGE_FIND_FILE})
endif()

include_directories(${NATIVERENDER_ROOT_PATH}
                    ${NATIVERENDER_ROOT_PATH}/include)

add_library(entry SHARED napi_init.cpp)
target_link_libraries(entry PUBLIC libace_napi.z.so)
# 设备信息
target_link_libraries(entry PUBLIC libdeviceinfo_ndk.z.so)

实现

在 napi_init.cpp 里定义一个函数 GetDeviceInfo,实现具体设备信息获取的逻辑

导包

#include "napi/native_api.h"
#include "deviceinfo.h"
#include <cstdlib>
#include <cstring>
#include <string>

/**
 * 获取设备信息
 * @param env
 * @param 
 * @return
 */
static napi_value GetDeviceInfo(napi_env env, napi_callback_info) {

    std::string deviceType = "设备类型: " + std::string(OH_GetDeviceType()) + "\n";
    std::string manufacture = "设备制造商: " + std::string(OH_GetManufacture()) + "\n";
    std::string brand = "设备设备品牌: " + std::string(OH_GetBrand()) + "\n";
    std::string marketName = "外部产品系列: " + std::string(OH_GetMarketName()) + "\n";
    std::string productSeries = "产品系列: " + std::string(OH_GetProductSeries()) + "\n";
    std::string productModel = "认证型号: " + std::string(OH_GetProductModel()) + "\n";
    std::string softwareModel = "内部软件子型号: " + std::string(OH_GetSoftwareModel()) + "\n";
    std::string hardwareModel = "硬件版本号: " + std::string(OH_GetHardwareModel()) + "\n";
    std::string bootloaderVersion = "Bootloader版本号: " + std::string(OH_GetBootloaderVersion()) + "\n";
    std::string abiList = "应用二进制接口（Abi）: " + std::string(OH_GetAbiList()) + "\n";
    std::string securityPatchTag = "安全补丁级别: " + std::string(OH_GetSecurityPatchTag()) + "\n";
    std::string displayVersion = "产品版本: " + std::string(OH_GetDisplayVersion()) + "\n";
    std::string IncrementalVersion = "差异版本: " + std::string(OH_GetIncrementalVersion()) + "\n";
    std::string OSReleaseType = "系统的发布类型: " + std::string(OH_GetOsReleaseType()) + "\n";
    std::string OSFullName = "完整的系统版本名: " + std::string(OH_GetOSFullName()) + "\n";
    std::string sdkApiVersion = "系统软件API版本: " + std::to_string(OH_GetSdkApiVersion()) + "\n";
    std::string firstApiVersion = "首个版本系统软件API版本: " + std::to_string(OH_GetFirstApiVersion()) + "\n";
    std::string versionId = "版本ID: " + std::string(OH_GetVersionId()) + "\n";
    std::string buildType = "系统的构建类型: " + std::string(OH_GetBuildType()) + "\n";
    std::string buildUser = "系统的构建用户: " + std::string(OH_GetBuildUser()) + "\n";
    std::string buildHost = "系统的构建主机: " + std::string(OH_GetBuildHost()) + "\n";
    std::string buildTime = "完整系统的构建时间: " + std::string(OH_GetBuildTime()) + "\n";
    std::string buildRootHash = "系统的构建版本Hash: " + std::string(OH_GetBuildRootHash()) + "\n";
    std::string distributionOSName = "ISV发行系统版本名称: " + std::string(OH_GetDistributionOSName()) + "\n";
    std::string distributionOSVersion = "ISV发行版系统版本号: " + std::string(OH_GetDistributionOSVersion()) + "\n";
    std::string distributionOSApiVersion ="ISV发行版系统api版本: " + std::to_string(OH_GetDistributionOSApiVersion()) + "\n";
    std::string distributionOSReleaseType ="ISV发行版系统类型: " + std::string(OH_GetDistributionOSReleaseType()) + "\n";

    // 获取每个属性的长度
    size_t length1 = strlen(deviceType.c_str());
    size_t length2 = strlen(manufacture.c_str());
    size_t length3 = strlen(brand.c_str());
    size_t length4 = strlen(marketName.c_str());
    size_t length5 = strlen(productSeries.c_str());
    size_t length6 = strlen(productModel.c_str());
    size_t length7 = strlen(softwareModel.c_str());
    size_t length8 = strlen(hardwareModel.c_str());
    size_t length9 = strlen(bootloaderVersion.c_str());
    size_t length10 = strlen(abiList.c_str());
    size_t length11 = strlen(securityPatchTag.c_str());
    size_t length12 = strlen(displayVersion.c_str());
    size_t length13 = strlen(IncrementalVersion.c_str());
    size_t length14 = strlen(OSReleaseType.c_str());
    size_t length15 = strlen(OSFullName.c_str());
    size_t length16 = strlen(sdkApiVersion.c_str());
    size_t length17 = strlen(firstApiVersion.c_str());
    size_t length18 = strlen(versionId.c_str());
    size_t length19 = strlen(buildType.c_str());
    size_t length20 = strlen(buildUser.c_str());
    size_t length21 = strlen(buildHost.c_str());
    size_t length22 = strlen(buildTime.c_str());
    size_t length23 = strlen(buildRootHash.c_str());
    size_t length24 = strlen(distributionOSName.c_str());
    size_t length25 = strlen(distributionOSVersion.c_str());
    size_t length26 = strlen(distributionOSApiVersion.c_str());
    size_t length27 = strlen(distributionOSReleaseType.c_str());

    // 计算拼接后的长度
    size_t resultLength = length1 + length2 + length3 + length4 + length5 + length6 + length7 + length8 + length9 +
                          length10 + length11 + length12 + length13 + length14 + length15 + length16 + length17 +
                          length18 + length19 + length20 + length21 + length22 + length23 + length24 + length25 +
                          length26 + length27;

    // 分配内存以存储拼接后的字符串
    char *resultStr = (char *)malloc(resultLength + 1);
    // 拼接字符串
    strcpy(resultStr, deviceType.c_str());
    strcat(resultStr, manufacture.c_str());
    strcat(resultStr, brand.c_str());
    strcat(resultStr, marketName.c_str());
    strcat(resultStr, productSeries.c_str());
    strcat(resultStr, productModel.c_str());
    strcat(resultStr, softwareModel.c_str());
    strcat(resultStr, hardwareModel.c_str());
    strcat(resultStr, bootloaderVersion.c_str());
    strcat(resultStr, abiList.c_str());
    strcat(resultStr, securityPatchTag.c_str());
    strcat(resultStr, displayVersion.c_str());
    strcat(resultStr, IncrementalVersion.c_str());
    strcat(resultStr, OSReleaseType.c_str());
    strcat(resultStr, OSFullName.c_str());
    strcat(resultStr, sdkApiVersion.c_str());
    strcat(resultStr, firstApiVersion.c_str());
    strcat(resultStr, versionId.c_str());
    strcat(resultStr, buildType.c_str());
    strcat(resultStr, buildUser.c_str());
    strcat(resultStr, buildHost.c_str());
    strcat(resultStr, buildTime.c_str());
    strcat(resultStr, buildRootHash.c_str());
    strcat(resultStr, distributionOSName.c_str());
    strcat(resultStr, distributionOSVersion.c_str());
    strcat(resultStr, distributionOSApiVersion.c_str());
    strcat(resultStr, distributionOSReleaseType.c_str());

    napi_value result;
    napi_create_string_utf8(env, resultStr, resultLength, &result);
    return result;
}

配置

EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports) {
   
    napi_property_descriptor desc[] = {
        // 设备信息
        {"getDeviceInfo", nullptr, GetDeviceInfo, nullptr, nullptr, nullptr, napi_default, nullptr}
    };
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}

定义模块

EXTERN_C_END
static napi_module demoModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = ((void *)0),
    .reserved = {0},
};

注册模块

1	extern "C" __attribute__((constructor)) void RegisterEntryModule(void) { napi_module_register(&demoModule); }

定义调用函数

index.d.ts

1	export const getDeviceInfo: () => string;

引入

1	import { getDeviceInfo } from 'libentry.so';

调用

1 2	val deviceinfo = getDeviceInfo(); console.error(deviceinfo);

运行项目

输出

12-19 11:08:10.384   21645-21645   A03D00/com.../JSAPP  com.xw....lication   E     设备类型： phone, 厂家：HUAWEI, 品牌：HUAWEI, 外部产品系列：HUAWEI Mate 60, 产品系列：BRA, 认证型号：BRA-AL00, 内部软件子型号：BRA-AL00, 硬件版本号：HL1FLSM, 硬件Profile：default, Bootloader版本号：bootloader, 应用二进制接口（Abi）列表：arm64-v8a, 安全补丁级别：2024/11/01, 产品版本：BRA-AL00 5.0.0.110(SP6C00E107R4P22), 差异版本号：default, 系统的发布类型：Beta3, 系统版本：OpenHarmony-5.0.1.107(Beta3), Major版本号：5, Senior版本号：0, Feature版本号：1, Build版本号：107, 系统软件API版本：13, 首个版本系统软件API版本：1, 版本ID：phone/HUAWEI/HUAWEI/BRA/OpenHarmony-5.0.1.107(Beta3)/BRA-AL00/BRA-AL00/13/default/default, 构建类型：default, 构建用户：default, 构建主机：default, 构建时间：default, 构建版本Hash：default, 发行版系统名称：, 发行版系统版本号：5.0.0, 发行版系统api版本：50001, 发行版系统api版本名称：5.0.1, 发行版系统类型：Beta3, 开发者匿名设备标识符(ODID): 2699128d-5975-8985-8af4-bb30ce52....

效果图

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