ionic cordova 从 sdcard 获取所有 mp3 文件

Question

我正在开发一个音乐应用程序，我需要从 android 设备中检索所有 mp3 文件。我如何使用 ionic 和 cordova 来做到这一点？

我曾尝试使用cordova 文件插件，但我什至找不到列出目录中所有文件的方法。请帮忙。

 window.resolveLocalFileSystemURI(cordova.file.externalRootDirectory, function(fileSystem) {
   var directoryReader = fileSystem.createReader();
   directoryReader.readEntries(function(entries) {
     //alert(JSON.stringify(directoryReader));
     for(i=0;i<entries.length;i++)
     {
       alert(JSON.stringify(entries[i].name));

     }
     //alert(entries);
     //console.log(entries);
   });
 });

上面的代码只是给出了sd卡中的目录名。我需要一个逻辑来从所有目录和子目录中查找 mp3 文件。

Answer 1

如果有人想知道如何在 ionic2/3 上执行此操作，我们可以使用 cordova-plugin-file 从系统中检索所有文件。

首先安装cordova-file-plugin。

将此插件添加到您应用的模块中。

然后像这样在任何你想要的地方使用它。

import { FilePath } from '@ionic-native/file-path';
import { File } from '@ionic-native/file';
constructor(....
            , public filePath: FilePath
            , public platform: Platform
            , public file: File ) {
    this.platform.ready().then(() => {
      //the first parameter file.externalRootDirectory is for listing all files on application's root directory
      //The second parameter is the name of the folder. You can specify the nested folder here. e.g. 'Music/Coldplay'
      file.listDir(file.externalRootDirectory, '').then((result) => {
        for(let item of result)
        {
          if(item.isDirectory == true && item.name != '.' && item.name!= '..')
          {
            this.getFileList(item.name);//Get all the files inside the folder. recursion will probably be useful here.
          }
          else if (item.isFile == true)
          { 
            //File found
            this._fileList.push({
              name: item.name,
              path: item.fullPath
            });
          }
        }
      },
      (error) => {
        console.log(error);
      });      
    })
  }

  public getFileList(path: string): any
  {
    let file = new File();
    this.file.listDir(file.externalRootDirectory, path)
    .then((result)=>{
      for(let item of result)
      {
        if(item.isDirectory == true && item.name != '.' && item.name != '..')
        {
          this.getFileList(path + '/' + item.name);
        }
        else
        {
          this._fileList.push({
            name: item.name,
            path: item.fullPath
          })
        }
      }
    },(error)=>{
      console.log(error);
    })
  }

**您可以通过在提取过程中某处比较扩展类型来过滤音频文件

Complete cordova documentation

Ionic documentation

Answer 2

此例程将列出所选文件系统中的所有文件和文件夹。

    import { File } from "@ionic-native/file";
    import { Diagnostic } from "@ionic-native/diagnostic";

    constructor(
        ...
        public file: File,
        public diagnostic: Diagnostic
        ){


  // -------------------------
  listFileSys( which){

    // <which> chooses the file system - see switch below
    this.jcDebug += "\n" + "listFileSysSKOFLO(" + which + ")";

    let fileSysArray = [];
    let basePath = "";

    let tag = "unknown";

    // ************** RECURSE *************
    let jcListDir = (thisDir)=>{

      tag = "jcListDir: [" + thisDir + "]";

      this.file.listDir(basePath, thisDir)
      .then( (data)=>{
        tag = "listDir:" + thisDir;
        this.jcError += "\n" + tag + ":" + JSON.stringify( data);
        for( let ii = 0; ii < data.length; ii += 1){
          this.jcError += "\n" + data[ii].name + (data[ii].isDirectory? " [D]" : " [F]");

          let currentPath = thisDir;
          currentPath += (currentPath.length ? "/" : "");
          currentPath += data[ii].name;
          this.jcError += "\n" + "currentPath:" + currentPath;

          fileSysArray.push( currentPath);

          if( data[ii].isDirectory && ok2recurse){
            jcListDir( currentPath);         // RECURSE !!!
          }
        }
      }, (errData)=>{
        tag = "listDir";
        this.jcError += "\n" + tag + ":ERR:" + JSON.stringify( errData);
      });
    };
    // ************** RECURSE *************

    // ***********************
    let runListDir = ()=>{
        this.jcDebug += "\n" + "basePath:" + basePath;

        // !!! START listing from basePath !!!
        jcListDir( ".");
    }

    // ***********************
    switch( which)
    {
      case 1:
        this.diagnostic.getExternalSdCardDetails()
        .then( (data) => {
          this.jcDebug += "\n" + "sd:" + JSON.stringify( data);
          this.jcDebug += "\n" + "Number of cards: " + data.length;
          for( let ii = 0; ii < data.length; ii += 1){
            let thisElem = data[ii];
            if( thisElem.type.toLowerCase() === "application" && thisElem.canWrite){
              basePath = thisElem.filePath;
              break;
            }
          }
          if( !basePath){
            this.jcDebug += "\n" + "no SD card found";
            return;
          }
          runListDir();
        }, (errData)=>{
          tag = "getExternalSdCardDetails";
          this.jcError += "\n" + tag + ":ERR:" + JSON.stringify( errData);
        });
      break;
      case 2:
        basePath = this.file.externalDataDirectory;
        this.jcError += "\n" + "externalDataDirectory:" + basePath;
        runListDir();
        break;
      case 3:
        basePath = this.file.dataDirectory;
        this.jcError += "\n" + "dataDirectory:";
        runListDir();
        break;
      default:
        alert( "which???:" + which);
        return;
    }

    // wait for all to comnplete, then show
    // assume 1000 ms is adequate delay per promise
    let lastFileSysLen = -1
    let checkCount = 30; // max 30 * 1000 ms = 30 seconds

    // ************** RECURSE *************
      let checkComplete = () => {
      this.jcDebug += "\n" + "checkComplete " + checkCount + " [" + fileSysArray.length + "]";
      setTimeout( ()=>{

        // fileSysArr length stable?
        if( fileSysArray.length === lastFileSysLen){
          checkCount = 0;
        }
        lastFileSysLen = fileSysArray.length;

        checkCount -= 1;
        if( checkCount > 0){
          checkComplete();    // recurse
        } else {

          // STOP !!! and show FileSysArray
          this.jcInfo += "\n" + "show FileSysArray";
          this.jcInfo += "\n" + "fileSysArray.length = " + " [" + fileSysArray.length + "]";

          fileSysArray.sort();

          for( let elem of fileSysArray){
            this.jcInfo += "\n" + elem;
          }
        }
      }, 1000);
    };
    // ************** RECURSE *************
    checkComplete();
  }

必须有更好的方法来确定承诺何时全部解决......