如何使用Ionic File，Media和Media Object获取文件持续时间？

Question

我正在使用Ionic 3，我使用了名为Ionic Native - Media和Ionic File的原生插件。我在Android中使用我的移动设备成功录制音频，播放按钮工作正常。但是我想获得音频文件的持续时间并显示持续时间的总长度。我还想显示单击按钮时的当前持续时间。

这是我home.html中的代码

<ion-header>
  <ion-navbar>
    <ion-title>
      Sound Recorder & Player
    </ion-title>
  </ion-navbar>
</ion-header>

<ion-content padding>
  <ion-card>
    <ion-card-content>
      <ion-card-title>
        <button ion-button primary (click)="stopRecord()" *ngIf="recording"><ion-icon name="mic-off"></ion-icon>&nbsp;&nbsp;Stop Record</button>
        <button ion-button primary (click)="startRecord()" *ngIf="!recording"><ion-icon name="mic"></ion-icon>&nbsp;&nbsp;Start Record</button>
      </ion-card-title>
    </ion-card-content>
  </ion-card>
  <ion-list>
    <ion-item *ngFor="let audio of audioList; index as i;">
      <p>{{audio.filename}}</p>
      <button ion-button clear item-end large (click)="playAudio(audio.filename, i)"><ion-icon name="play"></ion-icon></button>
    </ion-item>
  </ion-list>
</ion-content>

这是我家里的代码

import { Component } from '@angular/core';
import { NavController, Platform } from 'ionic-angular';
import { Media, MediaObject } from '@ionic-native/media';
import { File } from '@ionic-native/file';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  recording: boolean = false;
  filePath: string;
  fileName: string;
  audio: MediaObject;
  audioList: any[] = [];

  constructor(
    public navCtrl: NavController,
    private media: Media,
    private file: File,
    public platform: Platform
  ) {

  }

  ionViewWillEnter() {
    this.getAudioList();
  }

  getAudioList() {
    if(localStorage.getItem("audiolist")) {
      this.audioList = JSON.parse(localStorage.getItem("audiolist"));
      console.log(this.audioList);
    }
  }

  startRecord() {
    if (this.platform.is('ios')) {
      this.fileName = 'record'+new Date().getDate()+new Date().getMonth()+new Date().getFullYear()+new Date().getHours()+new Date().getMinutes()+new Date().getSeconds()+'.3gp';
      this.filePath = this.file.documentsDirectory.replace(/file:\/\//g, '') + this.fileName;
      this.audio = this.media.create(this.filePath);
    } else if (this.platform.is('android')) {
      this.fileName = 'record'+new Date().getDate()+new Date().getMonth()+new Date().getFullYear()+new Date().getHours()+new Date().getMinutes()+new Date().getSeconds()+'.3gp';
      this.filePath = this.file.externalDataDirectory.replace(/file:\/\//g, '') + this.fileName;
      this.audio = this.media.create(this.filePath);
      let duration = this.audio.getDuration();
      console.log(duration)
    }
    this.audio.startRecord();
    this.recording = true;
  }

  stopRecord() {
    this.audio.stopRecord();
    let duration = this.audio.getDuration()
    console.log(duration)
    let data = { filename: this.fileName };
    this.audioList.push(data);
    localStorage.setItem("audiolist", JSON.stringify(this.audioList));
    this.recording = false;
    this.getAudioList();
  }

  playAudio(file,idx) {
    if (this.platform.is('ios')) {
      this.filePath = this.file.documentsDirectory.replace(/file:\/\//g, '') + file;
      this.audio = this.media.create(this.filePath);
    } else if (this.platform.is('android')) {
      this.filePath = this.file.externalDataDirectory.replace(/file:\/\//g, '') + file;
      this.audio = this.media.create(this.filePath);
      let duration = this.audio.getDuration()
      console.log('Duration:', duration)
    }
    this.audio.play();
    this.audio.setVolume(1.0);
  }

}

我试图console.log getDuration()函数，写在Media的文档中。然而它总是让我回归-1

这有什么想法？

感谢有人可以提供帮助。提前致谢。

Answer 1

您正在使用：

let duration = this.audio.getDuration();
  console.log(duration)

在开始录制之前：

 if (this.platform.is('ios')) {
  this.fileName = 'record'+new Date().getDate()+new Date().getMonth()+new Date().getFullYear()+new Date().getHours()+new Date().getMinutes()+new Date().getSeconds()+'.3gp';
  this.filePath = this.file.documentsDirectory.replace(/file:\/\//g, '') + this.fileName;
  this.audio = this.media.create(this.filePath);
} else if (this.platform.is('android')) {
  this.fileName = 'record'+new Date().getDate()+new Date().getMonth()+new Date().getFullYear()+new Date().getHours()+new Date().getMinutes()+new Date().getSeconds()+'.3gp';
  this.filePath = this.file.externalDataDirectory.replace(/file:\/\//g, '') + this.fileName;
  this.audio = this.media.create(this.filePath);
  ------>let duration = this.audio.getDuration();<-----
  console.log(duration)
}
------>this.audio.startRecord();<-----
this.recording = true;

你确定你正在寻找正确的console.log()？，尝试删除第一个console.log()。