# NativeDataConversion

**Repository Path**: harmony-os_6/NativeDataConversion

## Basic Information

- **Project Name**: NativeDataConversion
- **Description**: 本示例介绍如何使用DevEco Studio创建一个Native C++应用，将ArkTS侧的数据（基础的数据类型）传递到Native侧进行处理并返回结果到ArkTS侧。
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 7
- **Created**: 2024-11-14
- **Last Updated**: 2024-11-14

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Basic Data Type Conversion

## Overview
This sample shows how to use DevEco Studio to create a native C++ app, pass ArkTS data (of basic data types) to native for processing, and return the result to ArkTS.

## Preview

![synchronized_operation](screenshots/device/data_conversion.en.gif)

### Project Directory
```
├──conversion/src/main/cpp                    // C++ code
│  ├──types
│  │  └──libconversion                        // C++ APIs
│  │     ├──index.d.ts                        
│  │     └──oh-package.josn5                 
│  ├──ArraybufferType.cpp                     // ArrayBuffer conversion
│  ├──ArraybufferType.h                       
│  ├──ArrayType.cpp                           // Array conversion
│  ├──ArrayType.h
│  ├──CMakeLists.txt                          // CMake file
│  ├──DateType.txt                            // Date conversion
│  ├──DateType.h
│  ├──hello.cpp                               // Native module                             
│  ├──NumberType.cpp                          // Number conversion
│  ├──NumberType.h                          
│  ├──ObjectType.cpp                          // Object conversion
│  ├──ObjectType.h                            
│  ├──StringBoolType.cpp                      // string and boolean type conversion
│  └──StringBoolType.h                        
├──conversion/src/main/ets                    // ets code
│  ├──common
│  │  ├──constants  
│  │  │  └──CommonConstants.ets               // Constants
│  │  └──utils
│  │     └──Logger.ets                        // Logging utility
│  ├──conversionability
│  │  └──ConversionAbility.ets       
│  └──pages
│     ├──ArraybufferType.ets                  // ArrayBuffer conversion page
│     ├──ArrayType.ets                        // Array conversion page
│     ├──DateType.ets                         // Date conversion page
│     └──Index.ets                            // Home page
│     ├──NumberType.ets                       // Number conversion type
│     ├──ObjectType.ets                       // Object conversion type
│     ├──StringBoolType.ets                   // String and boolean type conversion page
│     └──Types.ts                             // object APIs
└──entry/src/main/resources                   // Static resources of the app
```

### Concepts
- Node-API: Node-API, formerly known as N-API), provides a set of APIs for building native addons in Node.js. It allows developers to write C/C++ code that interacts with JavaScript code. Currently, only some Node-API interfaces are supports.
- Currently, the following Node-API standard libraries are supported: C Standard Library, C++ library, OpenSL ES, and zlib.

### Required Permissions

N/A

### How to Use

1. On the home page, tap different types of data conversion to go to the corresponding data conversion pages.
2. Process data.
   - Add data of int type. 

     Use **napi_get_value_int32()** and **napi_create_int32 ()** to obtain and construct int data, respectively.

   - Concatenate strings (data of string type and boolean type) 

     Use **napi_get_value_string_utf8()**, **napi_get_value_bool()**, and **napi_create_string_utf8()**.

   - Obtain an array in reverse order (data of arr type). 

     Use **napi_get_array_length()**, **napi_create_array_with_length()**, **napi_get_element ()**, and **napi_set_element ()**. Obtain the length of the array, and then construct an array of the length obtained. Use **napi_get_element()** to obtain the value of each element in an array, and use **napi_set_element ()** to assign a value to each element.

   - Calculate the square for an **ArrayBuffer** (data of the **ArrayBuffer** type). 

     Use **napi_get_arraybuffer_info()** and **napi_create_external_arraybuffer()**. Use **napi_get_arraybuffer_info()** to obtain the pointer to the underlying buffer and the pointer length. To modify data, use **reinterpret_cast** to convert the pointer to a uint pointer and modify data. After the modification, use **reinterpret_cast** to convert the pointer back to a viod pointer. The pointer is referenced when **napi_create_external_arraybuffer()** is called to construct a new **ArrayBuffer**.

   - Assign a value to an object (data of the object type). 

     Use **napi_create_object ()** and **napi_set_named_property()**. You need to construct an object and use **napi_set_named_property()** to assign a value to a property of the object.

   - Convert data of the date type. 

     Use **napi_create_date ()** to create an object of the date type, and use **napi_get_date_value()** to parse the object.

### Constraints

1. The sample app is supported only on Huawei phones running the standard system.
2. The HarmonyOS version must be HarmonyOS NEXT Developer Beta 3 or later.
3. The DevEco Studio version must be DevEco Studio NEXT Developer Beta 3 or later.
4. The HarmonyOS SDK version must be HarmonyOS NEXT Developer Beta 3 SDK or later.