鸿蒙-使用系统文件预览不同类型的本地文件

SDK 版本：HarmonyOS NEXT Developer Beta2 SDK (5.0.0.31)
DevEco-Studio 版本：DevEco Studio NEXT Developer Beta2 (5.0.3.502）
工程机版本：ALN-AL00 NEXT.0.0.31

使用系统文件预览不同类型的本地文件

MediaUtils.ets

/*
 * Copyright (c) 2024. Dench.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { fileUri } from "@kit.CoreFileKit";
import { BusinessError } from "@kit.BasicServicesKit";
import { filePreview } from "@kit.PreviewKit";
import { uniformTypeDescriptor } from "@kit.ArkData";

/**
 * filePreview（文件预览）
 */
export function openSystemPreview(context: Context, path: string) {
  // let uiContext = getContext(this);
  // let displayInfo: filePreview.DisplayInfo = {
  //   x: 100,
  //   y: 100,
  //   width: 800,
  //   height: 800
  // };
  const uri = fileUri.getUriFromPath(path);
  const mimeType = getFileMimeType(path);
  console.info("uri:" + uri);
  console.info("mimeType:" + mimeType);
  let fileInfo: filePreview.PreviewInfo = {
    uri: uri,
    mimeType: mimeType,
  };
  filePreview
    .openPreview(context, fileInfo)
    .then(() => {
      console.info("Succeeded in opening preview");
    })
    .catch((err: BusinessError) => {
      console.error(
        `Failed to open preview, err.code = ${err.code}, err.message = ${err.message}`
      );
    });
}

/**
 * 根据文件后缀查询对应文件的 mimeType
 */
export function getFileMimeType(path: string): string {
  if (path.indexOf(".") != -1) {
    try {
      const ext = "." + path.split(".").pop();
      console.info("ext:" + ext);
      // 2.可根据 “.mp3” 文件后缀查询对应UTD数据类型，并查询对应UTD数据类型的具体属性
      let typeId1 =
        uniformTypeDescriptor.getUniformDataTypeByFilenameExtension(ext);
      console.info("typeId1:" + typeId1);
      let typeObj1 = uniformTypeDescriptor.getTypeDescriptor(typeId1);
      // console.info('typeId:' + typeObj1.typeId);
      console.info("belongingToTypes:" + typeObj1.belongingToTypes);
      // console.info('description:' + typeObj1.description);
      // console.info('referenceURL:' + typeObj1.referenceURL);
      // console.info('filenameExtensions:' + typeObj1.filenameExtensions);
      console.info("mimeTypes:" + typeObj1.mimeTypes);
      return typeObj1.mimeTypes[0];
    } catch (e) {}
  }
  return "text/plain";
}

Reference

https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/preview-arkts-V5#section1081123302517

https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/uniform-data-type-descriptors-V5