HarmonyOS 开发实践——基于ImageKit对图片进行处理

const context : Context = getContext(this);
const filePath : string = context.cacheDir + '/test.jpg';

const context = getContext(this);
const filePath = context.cacheDir + '/test.jpg';
const file : fs.File = fs.openSync(filePath, fs.OpenMode.READ_WRITE);
const fd : number = file?.fd;

const context : Context = getContext(this);
// 获取resourceManager资源管理器
const resourceMgr : resourceManager.ResourceManager = context.resourceManager;
resourceMgr.getRawFileContent('test.jpg').then((fileData : Uint8Array) => {
  console.log("Succeeded in getting RawFileContent")
  // 获取图片的ArrayBuffer
  const buffer = fileData.buffer.slice(0);
}).catch((err : BusinessError) => {
  console.error("Failed to get RawFileContent")
});

const context : Context = getContext(this);
// 获取resourceManager资源管理器
const resourceMgr : resourceManager.ResourceManager = context.resourceManager;
resourceMgr.getRawFd('test.jpg').then((rawFileDescriptor : resourceManager.RawFileDescriptor) => {
  console.log("Succeeded in getting resourceManager")
}).catch((err : BusinessError) => {
  console.error("Failed to get resourceManager")
});

// path为已获得的沙箱路径
const imageSource : image.ImageSource = image.createImageSource(filePath);

// fd为已获得的文件描述符
const imageSource : image.ImageSource = image.createImageSource(fd);

const imageSource : image.ImageSource = image.createImageSource(buffer);

const imageSource : image.ImageSource = image.createImageSource(rawFileDescriptor);

let decodingOptions : image.DecodingOptions = {
  editable: true,
  desiredPixelFormat: 3,
}
// 创建pixelMap并进行简单的旋转和缩放
imageSource.createPixelMap(decodingOptions).then((pixelMap : image.PixelMap) => {
  // 顺时针旋转90°
  pixelMap.rotate(90);
 
  // 宽为原来的0.5
  // 高为原来的0.5
  pixelMap.scale(0.5, 0.5);
  console.log("Succeeded in creating PixelMap")
}).catch((err : BusinessError) => {
  console.error("Failed to create PixelMap")
});

const imagePackerApi = image.createImagePacker();

let packOpts : image.PackingOption = { format:"image/jpeg", quality:98 };

import {BusinessError} from '@ohos.base'
import fs from '@ohos.file.fs'
const context : Context = getContext(this);
const path : string = context.cacheDir + "/pixel_map.jpg";
let file = fs.openSync(path, fs.OpenMode.CREATE | fs.OpenMode.READ_WRITE);
imagePackerApi.packToFile(pixelMap, file.fd, packOpts).then(() => {
  // 直接打包进文件
}).catch((error : BusinessError) => {
  console.error('Failed to pack the image. And the error is: ' + error);
})

import {BusinessError} from '@ohos.base'
import fs from '@ohos.file.fs'
const context : Context = getContext(this);
const filePath : string = context.cacheDir + "/image_source.jpg";
let file = fs.openSync(filePath, fs.OpenMode.CREATE | fs.OpenMode.READ_WRITE);
imagePackerApi.packToFile(imageSource, file.fd, packOpts).then(() => {
  // 直接打包进文件
}).catch((error : BusinessError) => {
  console.error('Failed to pack the image. And the error is: ' + error);
})

const path = getContext(this).filesDir + "imagenative.jpeg";
let file = fs.openSync(path, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
let fd =file.fd
testNapi.add1(this.pixelMap,fd)

napi_value packer;
int32_t result = OH_ImagePacker_Create(env, &packer);
ImagePacker_Native* nativePacker = OH_ImagePacker_InitNative(env, packer);

struct ImagePacker_Opts_ opts;
// 配置编码格式（必须）
opts.format = "image/jpeg";
// 配置编码质量（必须）
opts.quality = 98;

struct ImagePacker_Opts_ opts;
// 配置编码格式（必须）
opts.format = "image/jpeg";
// 配置编码质量（必须）
opts.quality = 98;