鸿蒙保存图片到相册

1.base64图片数据保存到相册

const base64Data: string = data as string
const base64Str = base64Data.split(',')[1];
const imgBuffer = buffer.from(base64Str, 'base64')
bufferArray = imgBuffer.buffer

const context = getContext();let helper = photoAccessHelper.getPhotoAccessHelper(context);let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'png', {title: fileName,})let file = await fileIo.open(uri, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE);// 写入图片fileIo.writeSync(file.fd, bufferArray);// 关闭文件await fileIo.close(file.fd);sysToast($r('app.string.toast_saved'))

2.base64图片数据转PixelMap

const base64Data: string = data as string const base64Str = base64Data.split(',')[1]; const imgBuffer = buffer.from(base64Str, 'base64')

bufferArray = imgBuffer.buffer

// 创建ImageSource
const imageSource = image.createImageSource(bufferArray);const decodingOptions : image.DecodingOptions = {desiredSize: { width: 0, height: 0 }, // 0表示使用原始尺寸desiredPixelFormat: image.PixelMapFormat.RGBA_8888,desiredRegion: { size: { width: 0, height: 0 }, x: 0, y: 0 }
};
const pixelMap = await imageSource.createPixelMap(decodingOptions);saveTo(pixelMap)

3.PixelMap转ArrayBuffer

const imagePackerApi = image.createImagePacker();
const packOpts: image.PackingOption = {format: 'image/jpeg', // 'image/jpeg' 或 'image/png'quality: 100    // 质量，对JPEG有效 (0-100)
};try {bufferArray = await imagePackerApi.packing(data, packOpts);
} catch (packError) {console.error(`Failed to pack image. Code: ${(packError as BusinessError).code}, message: ${(packError as BusinessError).message}`);
}

4. 从共享视频组件获取当前帧图像

const id = this.xComponentController.getXComponentSurfaceId(); const backgroundPix: PixelMap = await image.createPixelMapFromSurface(id);

5.叠加组合2个PixelMap

if (!foregroundPix || !backgroundPix) {return undefined;
}// 使用背景图片的尺寸作为目标尺寸
const imageInfo = await backgroundPix.getImageInfo()
const width = imageInfo.size.width;
const height = imageInfo.size.height;const canvas = new drawing.Canvas(backgroundPix);let rect: common2D.Rect = { left: 0, top: 0, right: width, bottom: height }
// 依次绘制每张图片
canvas.drawImageRect(foregroundPix, rect);return backgroundPix;