模板版本：v0.4.0

react-native-gcanvas

本项目基于 原库react-native-gcanvas 开发。

该第三方库支持直接从 npm 下载，包名为：@react-native-ohos/react-native-gcanvas 版本所属关系如下：

1、安装与使用

进入到工程目录并输入以下命令：

npm

npm install react-native-gcanvas@6.0.24
npm install @react-native-ohos/react-native-gcanvas

yarn

yarn add react-native-gcanvas@6.0.24
yarn add @react-native-ohos/react-native-gcanvas

下面的代码展示了这个库的基本使用场景：

import React from 'react';
import { View, StyleSheet, Text, ScrollView } from 'react-native';
import {GCanvasView} from '@flyskywhy/react-native-gcanvas';

const BasicShapesScreen: React.FC = () => {
  const drawRectangles = (canvas: any) => {
    const ctx = canvas.getContext('2d');
   
    ctx.fillStyle = '#FF6B6B';
    ctx.fillRect(10, 10, 60, 60);
    ctx.strokeStyle = '#4ECDC4';
    ctx.lineWidth = 3;
    ctx.strokeRect(80, 10, 60, 60);
    
    ctx.clearRect(25, 25, 30, 30);
    ctx.fillStyle = '#45B7D1';
    ctx.fillRect(10, 80, 130, 40);
    ctx.strokeStyle = '#FFFFFF';
    ctx.lineWidth = 2;
    ctx.strokeRect(20, 90, 110, 20);
  };
  
  const handleCanvasCreate = (canvas: any) => {
    setTimeout(() => {
      drawRectangles(canvas);
    }, 150);
  };

  return (
    <ScrollView style={styles.container}>
     <View style={styles.demoContainer}>
      <View style={styles.canvasWrapper}>
        <GCanvasView
          style={styles.canvas}
          isGestureResponsible={false}
          onCanvasCreate={handleCanvasCreate}
        />
      </View>
    </View>
    </ScrollView>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    padding: 16,
  },
  demoContainer: {
    marginBottom: 20,
    backgroundColor: '#FFFFFF',
    borderRadius: 12,
    padding: 16,
    shadowColor: '#000',
    shadowOffset: { width: 0, height: 2 },
    shadowOpacity: 0.1,
    shadowRadius: 4,
    elevation: 3,
  },
  canvasWrapper: {
    alignItems: 'center',
  },
  canvas: {
    width: 150,
    height: 120,
    backgroundColor: '#F8F9FA',
    borderRadius: 8,
  },
});

export default BasicShapesScreen;

2、Link

使用AutoLink的工程需要根据该文档配置，Autolink框架指导文档：https://gitcode.com/openharmony-sig/ohos_react_native/blob/master/docs/zh-cn/Autolinking.md

如您使用的版本支持 Autolink，并且工程已接入 Autolink，可跳过ManualLink配置。

{
  ...
  "overrides": {
    "@rnoh/react-native-openharmony" : "./react_native_openharmony",
  }
}

"dependencies": {
    "@rnoh/react-native-openharmony": "file:../react_native_openharmony",

    "@react-native-ohos/react-native-gcanvas": "file:../../node_modules/@react-native-ohos/react-native-gcanvas/harmony/gcanvas.har",
  }

cd entry
ohpm install

project(rnapp)
cmake_minimum_required(VERSION 3.4.1)
set(RNOH_APP_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
set(NODE_MODULES "${CMAKE_CURRENT_SOURCE_DIR}/../../../../../node_modules")
set(OH_MODULES "${CMAKE_CURRENT_SOURCE_DIR}/../../../oh_modules")
set(RNOH_CPP_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../../../../../../react-native-harmony/harmony/cpp")

add_subdirectory("${RNOH_CPP_DIR}" ./rn)

# RNOH_END: manual_package_linking_1
add_subdirectory("../../../../sample_package/src/main/cpp" ./sample-package)

+ add_subdirectory("${OH_MODULES}/@react-native-ohos/react-native-gcanvas/src/main/cpp" ./gcanvas)

# RNOH_END: manual_package_linking_1

add_library(rnoh_app SHARED
    "./PackageProvider.cpp"
    "${RNOH_CPP_DIR}/RNOHAppNapiBridge.cpp"
)

target_link_libraries(rnoh_app PUBLIC rnoh)

# RNOH_BEGIN: manual_package_linking_2
target_link_libraries(rnoh_app PUBLIC rnoh_sample_package)
+ target_link_libraries(rnoh_app PUBLIC rnoh_gcanvas)

# RNOH_BEGIN: manual_package_linking_2

#include "RNOH/PackageProvider.h"
#include "SamplePackage.h"
+ #include "RNCGCanvasPackage.h"
using namespace rnoh;

std::vector<std::shared_ptr<Package>> PackageProvider::getPackages(Package::Context ctx) {
    return {
      std::make_shared<SamplePackage>(ctx),
+     std::make_shared<RNCGCanvasPackage>(ctx)
    };
}

  ...
+ import RNCGCanvasPackage from '@react-native-ohos/react-native-gcanvas'

export function createRNPackages(ctx: RNPackageContext): RNPackage[] {
  return [
    new SamplePackage(ctx),
+   new RNCGCanvasPackage(ctx),
  ];
}

2.5. 运行

点击右上角的 sync 按钮

或者在终端执行：

cd entry
ohpm install

然后编译、运行即可。

3. 约束与限制

3.1.兼容性

本文档内容基于以下版本验证通过：

1. RNOH: 0.72.32; SDK: HarmonyOS 6.0.1.116 Release SDK; IDE: DevEco Studio 6.0.1.260; ROM: 6.0.0.130 SP15;
2. RNOH: 0.77.59; SDK: HarmonyOS 6.0.1.116 Release SDK; IDE: DevEco Studio 6.0.1.260; ROM: 6.0.0.130 SP15;
3. RNOH: 0.82.18; SDK: HarmonyOS 6.0.1.116 Release SDK; IDE: DevEco Studio 6.0.1.260; ROM: 6.0.0.130 SP15;

4. 属性/API

GCanvasView

GCanvas

GImage

CanvasRenderingContext2D

WebGLRenderingContext

对外导出的函数

5. 遗留问题

6. 其他

7. 开源协议

本项目基于 Apache License 2.0 ，请自由地享受和参与开源。