HarmonyOS 鸿蒙Next 截图保存到相册

您可以参考以下demo：

import componentSnapshot from '[@ohos](/user/ohos).arkui.componentSnapshot';
import image from '[@ohos](/user/ohos).multimedia.image';
import { photoAccessHelper } from '[@kit](/user/kit).MediaLibraryKit';
import fs from '[@ohos](/user/ohos).file.fs';
import abilityAccessCtrl, { Permissions } from '[@ohos](/user/ohos).abilityAccessCtrl';
import { BusinessError } from '[@ohos](/user/ohos).base';
import { common } from '[@kit](/user/kit).AbilityKit';

const permissions: Array<Permissions> = ['ohos.permission.WRITE_IMAGEVIDEO'];

function reqPermissionsFromUser(permissions: Array<Permissions>, context: common.UIAbilityContext): void {
  let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager();

  // requestPermissionsFromUser会判断权限的授权状态来决定是否唤起弹窗
  atManager.requestPermissionsFromUser(context, permissions).then((data) => {
    let grantStatus: Array<number> = data.authResults;
    let length: number = grantStatus.length;

    for (let i = 0; i < length; i++) {
      if (grantStatus[i] === 0) {
        // 用户授权，可以继续访问目标操作
      } else {
        // 用户拒绝授权，提示用户必须授权才能访问当前页面的功能，并引导用户到系统设置中打开相应的权限
        return;
      }
    }

    // 授权成功
  }).catch((err: BusinessError) => {
    console.error(`Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`);
  });
}

[@Entry](/user/Entry)
[@Component](/user/Component)
struct Index {
  [@State](/user/State) pixmap: image.PixelMap | undefined = undefined;

  aboutToAppear(): void {
    const context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext;
    reqPermissionsFromUser(permissions, context);
  }

  build() {
    Column() {
      Row() {
        Image(this.pixmap)
          .width(200)
          .height(200)
          .border({ color: Color.Black, width: 2 })
          .margin(5);

        Image($r('app.media.app_icon'))
          .autoResize(true)
          .width(200)
          .height(200)
          .margin(5)
          .id("root");
      }

      Button("click to generate UI snapshot")
        .onClick(() => {
          componentSnapshot.get("root")
            .then((pixmap: image.PixelMap) => {
              this.pixmap = pixmap;
              // 保存到相册
              let packOpts: image.PackingOption = { format: "image/jpeg", quality: 98 };
              const imagePackerApi = image.createImagePacker();

              imagePackerApi.packing(pixmap, packOpts).then(async (buffer: ArrayBuffer) => {
                try {
                  const context = getContext(this);
                  let helper = photoAccessHelper.getPhotoAccessHelper(context);
                  let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'png');
                  let file = await fs.open(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
                  await fs.write(file.fd, buffer);
                  // 关闭文件
                  await fs.close(file.fd);
                } catch (error) {
                  console.error("error is " + JSON.stringify(error));
                }
              }).catch((error: BusinessError) => {
                console.error('Failed to pack the image. And the error is: ' + error);
              });
            }).catch((err: Error) => {
              console.log("error: " + err);
            });
        }).margin(10);
    }
    .width('100%')
    .height('100%')
    .alignItems(HorizontalAlign.Center);
  }
}