C++同步调ArkTS里面的方法

napi_get_cb_info
napi_get_value_double
napi_create_double
napi_call_function

import hilog from '@ohos.hilog'; 
import testNapi from 'libentry.so'; 
 
@Entry 
@Component 
struct Index { 
  @State message: string = 'Hello World'; 
  //private resmgr = getContext().resourceManager;  // 获取js的资源对象 
 
  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)); 
            testNapi.addSync(3, 4, (result:number)=>{ 
              this.message = 'result is ' + result.toString(); 
            }); 
          }) 
      } 
      .width('100%') 
    } 
    .height('100%') 
  } 
}

static napi_value AddSync(napi_env env, napi_callback_info info) { 
    size_t requireArgc = 3; 
    size_t argc = 3; 
    napi_value args[3] = {nullptr}; 
napi_value context = nullptr; 
 
napi_get_cb_info(env, info, &argc, args, &context, 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 callBackArg[1] = {nullptr}; 
napi_create_double(env, value0 + value1, &callBackArg[0]); 
 
napi_value sum; 
napi_call_function(env, context, args[2], 1, callBackArg, &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}, 
{"addSync", nullptr, AddSync, nullptr, nullptr, nullptr, napi_default, nullptr} 
}; 
napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); 
return exports; 
} 
EXTERN_C_END

export const addSync: (a: number, b: number, callback:(result:number)=>void) => number;