# 使用JSVM-API实现JS与C/C++语言交互开发流程 使用JSVM-API实现跨语言交互，首先需按其机制注册和加载模块。 * ArkTS/JS侧：实现C++方法的调用。代码比较简单，import一个对应的so库后，即可调用C++方法。 * Native侧：.cpp文件，实现模块的注册。需要提供注册lib库的名称，并在注册回调方法中定义接口的映射关系，即Native方法及对应的JS/ArkTS接口名称等。 此处以在ArkTS/JS侧和Native侧实现RunTest()接口实现跨语言交互为例，展示使用JSVM-API进行跨语言交互的流程。 ## 创建Native C++工程 具体见[创建NDK工程](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/create-with-ndk) ## Native侧方法的实现 参考[使用Node-API实现跨语言交互开发流程](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/use-napi-process#native侧方法的实现)，以下代码提供了"使用JSVM-API实现JS与C/C++语言交互开发流程"Native侧方法实现的一个demo。 * 在index.d.ts文件中，提供JS侧的接口方法。 ```TypeScript export const runTest: () => void; ``` * 在oh-package.json5文件中将index.d.ts与cpp文件关联起来。 ```json { "name": "libentry.so", "types": "./index.d.ts", "version": "", "description": "Please describe the basic information." } ``` * 在CMakeLists.txt文件中配置CMake打包参数。 ```text # entry/src/main/cpp/CMakeLists.txt cmake_minimum_required(VERSION 3.4.1) project(JSVMDemo) set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR}) # 日志打印配置 add_definitions( "-DLOG_DOMAIN=0xd0d0" ) add_definitions( "-DLOG_TAG=\"testTag\"" ) include_directories(${NATIVERENDER_ROOT_PATH} ${NATIVERENDER_ROOT_PATH}/include) # 添加名为entry的库 add_library(entry SHARED hello.cpp) # 构建此可执行文件需要链接的库 target_link_libraries(entry PUBLIC libace_napi.z.so libjsvm.so libhilog_ndk.z.so) ``` * 新建entry/src/main/cpp/hello.cpp，实现Native侧的runTest接口。具体代码如下： #include "napi/native_api.h" #include "hilog/log.h" #include "ark_runtime/jsvm.h" #define LOG_DOMAIN 0x3200 #define LOG_TAG "APP" static int g_aa = 0; #define CHECK_RET(theCall) \ do { \ JSVM_Status cond = theCall; \ if ((cond) != JSVM_OK) { \ const JSVM_ExtendedErrorInfo *info; \ OH_JSVM_GetLastErrorInfo(env, &info); \ OH_LOG_ERROR(LOG_APP, "jsvm fail file: %{public}s line: %{public}d ret = %{public}d message = %{public}s", \ __FILE__, __LINE__, cond, info != nullptr ? info->errorMessage : ""); \ return -1; \ } \ } while (0) #define CHECK(theCall) \ do { \ JSVM_Status cond = theCall; \ if ((cond) != JSVM_OK) { \ OH_LOG_ERROR(LOG_APP, "jsvm fail file: %{public}s line: %{public}d ret = %{public}d", __FILE__, __LINE__, \ cond); \ return -1; \ } \ } while (0) // 用于调用theCall并检查其返回值是否为JSVM_OK。 // 如果不是，则调用OH_JSVM_GetLastErrorInfo处理错误并返回retVal。 #define JSVM_CALL_BASE(env, theCall, retVal) \ do { \ JSVM_Status cond = theCall; \ if (cond != JSVM_OK) { \ const JSVM_ExtendedErrorInfo *info; \ OH_JSVM_GetLastErrorInfo(env, &info); \ OH_LOG_ERROR(LOG_APP, "jsvm fail file: %{public}s line: %{public}d ret = %{public}d message = %{public}s", \ __FILE__, __LINE__, cond, info != nullptr ? info->errorMessage : ""); \ return retVal; \ } \ } while (0) // JSVM_CALL_BASE的简化版本，返回nullptr #define JSVM_CALL(theCall) JSVM_CALL_BASE(env, theCall, nullptr) // OH_JSVM_StrictEquals的样例方法 static JSVM_Value IsStrictEquals(JSVM_Env env, JSVM_CallbackInfo info) { // 接受两个入参 size_t argc = 2; JSVM_Value args[2] = {nullptr}; JSVM_CALL(OH_JSVM_GetCbInfo(env, info, &argc, args, nullptr, nullptr)); // 调用OH_JSVM_StrictEquals接口判断给定的两个JavaScript value是否严格相等 bool result = false; JSVM_Status status = OH_JSVM_StrictEquals(env, args[0], args[1], &result); if (status != JSVM_OK) { OH_LOG_ERROR(LOG_APP, "JSVM OH_JSVM_StrictEquals: failed"); } else { OH_LOG_INFO(LOG_APP, "JSVM OH_JSVM_StrictEquals: success: %{public}d", result); } JSVM_Value isStrictEqual; JSVM_CALL(OH_JSVM_GetBoolean(env, result, &isStrictEqual)); return isStrictEqual; } // IsStrictEquals注册回调 static JSVM_CallbackStruct param[] = { {.data = nullptr, .callback = IsStrictEquals}, }; static JSVM_CallbackStruct *method = param; // IsStrictEquals方法别名，供JS调用 static JSVM_PropertyDescriptor descriptor[] = { {"isStrictEquals", nullptr, method++, nullptr, nullptr, nullptr, JSVM_DEFAULT}, }; // 样例测试js const char *SRC_CALL_NATIVE = R"JS( let data = '123'; let value = 123; isStrictEquals(data, value);)JS"; static int32_t TestJSVM() { JSVM_InitOptions initOptions = {0}; JSVM_VM vm; JSVM_Env env = nullptr; JSVM_VMScope vmScope; JSVM_EnvScope envScope; JSVM_HandleScope handleScope; JSVM_Value result; // 初始化JavaScript引擎实例 if (g_aa == 0) { g_aa++; CHECK(OH_JSVM_Init(&initOptions)); } // 创建JSVM环境 CHECK(OH_JSVM_CreateVM(nullptr, &vm)); CHECK(OH_JSVM_OpenVMScope(vm, &vmScope)); CHECK(OH_JSVM_CreateEnv(vm, sizeof(descriptor) / sizeof(descriptor[0]), descriptor, &env)); CHECK_RET(OH_JSVM_OpenEnvScope(env, &envScope)); CHECK_RET(OH_JSVM_OpenHandleScope(env, &handleScope)); // 通过script调用测试函数 JSVM_Script script; JSVM_Value jsSrc; CHECK_RET(OH_JSVM_CreateStringUtf8(env, SRC_CALL_NATIVE, JSVM_AUTO_LENGTH, &jsSrc)); CHECK_RET(OH_JSVM_CompileScript(env, jsSrc, nullptr, 0, true, nullptr, &script)); CHECK_RET(OH_JSVM_RunScript(env, script, &result)); // 销毁JSVM环境 CHECK_RET(OH_JSVM_CloseHandleScope(env, handleScope)); CHECK_RET(OH_JSVM_CloseEnvScope(env, envScope)); CHECK(OH_JSVM_DestroyEnv(env)); CHECK(OH_JSVM_CloseVMScope(vm, vmScope)); CHECK(OH_JSVM_DestroyVM(vm)); return 0; } static napi_value RunTest(napi_env env, napi_callback_info info) { TestJSVM(); return nullptr; } // 模块注册信息，供arkts侧调用 EXTERN_C_START static napi_value Init(napi_env env, napi_value exports) { napi_property_descriptor desc[] = {{"runTest", nullptr, RunTest, 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); } ## ArkTS侧调用C/C++方法实现 ```TypeScript import napitest from 'libentry.so'; @Entry @Component struct Index { @State message: string = 'Hello World'; build() { Row() { Column() { Text(this.message) .fontSize(50) .fontWeight(FontWeight.Bold) .onClick(() => { try { napitest.runTest(); this.message = 'success'; } catch (error) { console.error('An error occurred: ', error); this.message = 'fail'; } }) } .width('100%') } .height('100%') } } ``` 预期输出结果 ```ts JSVM OH_JSVM_StrictEquals: success: 0 ```