HarmonyOS 鸿蒙Next napi_get_arraybuffer_info napi_create_arraybuffer 不知道在NDK中如何使用

发布于 1周前 作者 phonegap100 来自 鸿蒙OS

HarmonyOS 鸿蒙Next napi_get_arraybuffer_info napi_create_arraybuffer 不知道在NDK中如何使用

static napi_value TestArrayBuffer(napi_env env, napi_callback_info info) {
    size_t argc = 1;
    napi_value args[1] = {nullptr};
    napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);
    void *arrayBufferPtr = nullptr;
    size_t compareSize = 0;
    napi_status result = napi_get_arraybuffer_info(env, args[0], &arrayBufferPtr, &compareSize);
    napi_value arrayBuffer = nullptr;
    result = napi_create_arraybuffer(env, compareSize, &arrayBufferPtr, &arrayBuffer);
    return arrayBuffer;
}

console.log('testArrayBuffer的结果是=' + uint8ArrayToString(new Uint8Array(testNapi.testArrayBuffer(stringToUint8Array('test').buffer))));

let textEncoder = new util.TextEncoder('utf-8');
let textDecoder = util.TextDecoder.create('utf-8', { ignoreBOM: true });

export function stringToUint8Array(str: string): Uint8Array {
    return textEncoder.encodeInto(str);
}

export function uint8ArrayToString(data: Uint8Array) {
    return textDecoder.decodeWithStream(data, { stream: false });
}

上面的日志testArrayBuffer的结果是= 是空的，怎么改


更多关于HarmonyOS 鸿蒙Next napi_get_arraybuffer_info napi_create_arraybuffer 不知道在NDK中如何使用的实战系列教程也可以访问 https://www.itying.com/category-93-b0.html

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// TS array 传到NAPI层参考

static napi_value TS2NAPI(napi_env env, napi_callback_info info) { size_t argc = 1; napi_value args[1]; napi_get_cb_info(env, info, &argc, args, NULL, NULL); napi_value input_array = args[0];

napi_typedarray_type type;
napi_value input_buffer;
size_t byte_offset;
size_t i, length;
napi_get_typedarray_info(env, input_array, &type, &length, NULL, &input_buffer, &byte_offset);

void * data;
size_t byte_length;
napi_get_arraybuffer_info(env, input_buffer, &data, &byte_length);

napi_value output_buffer;
void * output_ptr = NULL;
napi_create_arraybuffer(env, byte_length, &output_ptr, &output_buffer);

napi_value output_array;
napi_create_typedarray(env, type, length, output_buffer, byte_offset, &output_array);

if (type == napi_uint8_array) {
    uint8_t * input_bytes = (uint8_t *)(data) + byte_offset;
    uint8_t * output_bytes = (uint8_t *)(output_ptr);
    for (i = 0; i < length; i++) {
        output_bytes[i] = (uint8_t)(input_bytes[i]);
    }
} else if (type == napi_float64_array) {
    double * input_doubles = (double *)((uint8_t *)(data) + byte_offset);
    double * output_doubles = (double *)(output_ptr);
    for (i = 0; i < length; i++) {
        output_doubles[i] = input_doubles[i];
    }
} else {
    napi_throw_error(env, NULL, "Typed array was of a type not expected by test.");
    return NULL;
}
return output_array;

}

接口说明官网：https://nodejs.cn/api/n-api.html#napi_get_arraybuffer_info_x000D_ /ets侧构造一个array

public toArrayBuffer() { let num = [49, 50, 51, 52, 53, 54, 55, 56, 57, 45, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57]; let inputBuffer = new Uint8Array(num); hilog.info(0x0000, TAG, 'inputBuffer: ’ + inputBuffer.length); //20

let outPutBuffer = testNapi.arrayBufferToNative(inputBuffer, 2)
hilog.info(0x0000, TAG, 'outPutBuffer: ' + outPutBuffer);

}

// index.d.ts声明 export const arrayBufferToNative: (inputBuff: object, length: number) => object; /对传入的buff做计算，数值乘以2返回

static napi_value Multiply(napi_env env, napi_callback_info info) { size_t argc = 2; napi_value args[2]; napi_get_cb_info(env, info, &argc, args, NULL, NULL); napi_value input_array = args[0];

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

napi_typedarray_type type;
napi_value input_buffer;
size_t byte_offset;
size_t i, length;
napi_get_typedarray_info(env, input_array, &type, &length, NULL, &input_buffer, &byte_offset);

void * data;
size_t byte_length;
napi_get_arraybuffer_info(env, input_buffer, &data, &byte_length);
napi_value output_buffer;
void * output_ptr = NULL;
napi_create_arraybuffer(env, byte_length, &output_ptr, &output_buffer);

napi_value output_array;
napi_create_typedarray(env, type, length, output_buffer, byte_offset, &output_array);

if (type == napi_uint8_array) {
    uint8_t * input_bytes = (uint8_t *)(data) + byte_offset;
    uint8_t * output_bytes = (uint8_t *)(output_ptr);
    for (i = 0; i < length; i++) {
        OH_LOG_INFO(LOG_APP, "Multiply_for_arraybuffer input_bytes % {public} d", input_bytes[i]);
        output_bytes[i] = (uint8_t)(input_bytes[i] * multiplier);
        OH_LOG_INFO(LOG_APP, "Multiply_for_arraybuffer output_bytes % {public} d", input_bytes[i]);
    }
} else if (type == napi_float64_array) {
    double * input_doubles = (double *)((uint8_t *)(data) + byte_offset);
    double * output_doubles = (double *)(output_ptr);
    for (i = 0; i < length; i++) {
        output_doubles[i] = input_doubles[i] * multiplier;
    }
} else {
    napi_throw_error(env, NULL, "Typed array was of a type not expected by test.");
    return NULL;
}
return output_array;

}

更多关于HarmonyOS 鸿蒙Next napi_get_arraybuffer_info napi_create_arraybuffer 不知道在NDK中如何使用的实战系列教程也可以访问 https://www.itying.com/category-93-b0.html


在HarmonyOS鸿蒙系统的NDK（Native Development Kit）中，napi_get_arraybuffer_info 和 napi_create_arraybuffer 是与N-API（Native Abstraction Interface）相关的函数，用于在原生代码中操作JavaScript的ArrayBuffer对象。以下是这两个函数在NDK中的基本使用方法：

  1. napi_get_arraybuffer_info

    用于获取ArrayBuffer的信息，包括其数据指针和字节长度。

    napi_status status = napi_get_arraybuffer_info(env, arraybuffer, &data, &byte_length);

    其中，env 是N-API环境句柄，arraybuffer 是要查询的ArrayBuffer对象，data 是指向数据指针的指针，byte_length 是指向字节长度的指针。

  2. napi_create_arraybuffer

    用于创建一个新的ArrayBuffer对象。

    napi_status status = napi_create_arraybuffer(env, byte_length, &data, &arraybuffer);

    其中，env 是N-API环境句柄，byte_length 是ArrayBuffer的字节长度，data 是指向新创建的ArrayBuffer数据指针的指针，arraybuffer 是指向新创建的ArrayBuffer对象的指针。

请注意，使用这些函数时，需要确保已正确初始化N-API环境，并遵循其生命周期管理规则。

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