在Ionic开发中，上传图片功能的代码实现讲解

前言

由于项目中涉及到用户上传修改头像，所以研究一下Ionic中上传图片的实现。

正文

由于代码中注释很详细，直接贴代码和注释

HTML代码：

<!-- 下拉刷新加载 -->  
<ion-content no-margin>  
  <ion-refresher (ionRefresh)="pullDown($event)">  
    <ion-refresher-content pullingIcon="arrow-dropdown" pullingText="{{Refresh}}" refreshingSpinner="circles" refreshingText="{{Refresh}}">  
    </ion-refresher-content>  
  </ion-refresher>  
  
  <!-- 显示图片，若没有图片则显示请从图库中选择一张图片 -->  
  <img src="{{pathForImage(lastImage)}}" style="width:100%;" [hidden]="lastImage === null" />  
  <h3>请从图库中选择一张图片</h3>  
</ion-content>  
  
<ion-footer>  
  <ion-toolbar color="primary">  
    <ion-buttons>  
      <button ion-button icon-left (click)="presentActionSheet()">  
        <ion-icon name="camera"></ion-icon>选择...  
      </button>  
      <!-- 如果没有选择图片，上传按钮为不可用状态 -->  
      <button ion-button icon-left (click)="uploadImage()" [disabled]="lastImage === null">  
        <ion-icon name="cloud-upload"></ion-icon>上传  
      </button>  
    </ion-buttons>  
  </ion-toolbar>  
</ion-footer>  

.ts代码

import { Component } from '@angular/core';
//判断是哪个平台打开的导入Platform
import { IonicPage, normalizeURL, NavController, NavParams, ActionSheetController, ToastController, ModalController, LoadingController, Platform, Loading, ViewController } from 'ionic-angular';

// 导入四个外部加载进来的组件
import { File } from "@ionic-native/file";
import { Transfer, TransferObject } from "@ionic-native/transfer";
import { FilePath } from "@ionic-native/file-path";
import { Camera } from "@ionic-native/camera";
import { BaseUI } from '../../../../common/baseui';

declare var cordova: any; //导入第三方的库定义到TS项目中

// @IonicPage()
@Component({
  selector: 'page-headface',
  templateUrl: 'headface.html',
})

export class HeadfacePage extends BaseUI {
  userId: string;
  errorMessage: string;
  lastImage: string = null;

  constructor(public navCtrl: NavController,
    public navParams: NavParams,
    public modalCtrl: ModalController,
    public loadingCtrl: LoadingController,
    public actionSheetCtrl: ActionSheetController,
    public camera: Camera,
    public transfer: Transfer,
    public file: File,
    public filePath: FilePath,
    public platform: Platform,
    public toastCtrl: ToastController,
    public viewCtrl: ViewController
  ) {
    super();
  }

  // ionViewDidEnter(){
  //   this.shorage.get('UserId').then(val)=>{
  //     if (val != null) {
  //       this.userId = val
  //     }
  //   }
  // }

  private Refresh: string;
  // 下拉刷新
  pullDown(goback) {
    this.Refresh = "这里不是入口";
    goback.complete();
  }

  presentActionSheet() {
    let actionSheet = this.actionSheetCtrl.create({
      title: '选择图片',
      buttons: [
        {
          text: '从图库中选择',
          handler: () => {
            this.takePicture(this.camera.PictureSourceType.PHOTOLIBRARY);
          }
        },
        {
          text: '使用相机',
          handler: () => {
            this.takePicture(this.camera.PictureSourceType.CAMERA);
          }
        },
        {
          text: '取消',
          role: 'cancel'
        }
      ]

    });
    actionSheet.present();
  }

  // 获取图片
  takePicture(sourceType) {
    // 定义相机的一些参数
    var options = {
      quality: 100,//图片的质量
      sourceType: sourceType,
      saveToPhotoAlbum: false, //是否把拍摄的照片保存到相册中
      correctOrientation: true,//是否纠正拍摄照片的方向-陀螺仪
    };
    //获取图片的方法
    this.camera.getPicture(options).then((imagePath) => {
      //特别处理Android平台的文件路径问题
      if (this.platform.is('android') && sourceType === this.camera.PictureSourceType.PHOTOLIBRARY) {
        //获取Android平台下的真实路径
        this.filePath.resolveNativePath(imagePath)
          .then(filePath => {
            //获取正确的路径
            let correctPath = filePath.substr(0, filePath.lastIndexOf('/') + 1);
            //获取正确的文件名
            let currentName = imagePath.substr(imagePath.lastIndexof('/') + 1);
            this.copyFileToLocalDir(correctPath, currentName, this.createFileName());
          });
      }
      else {
        //获取正确的路径
        let correctPath = imagePath.substr(0, imagePath.lastIndexOf('/') + 1);
        //获取正确的文件名
        let currentName = imagePath.substr(imagePath.lastIndexof('/') + 1);
        this.copyFileToLocalDir(correctPath, currentName, this.createFileName());
      }
    }, (err) => {
      super.showToast(this.toastCtrl, "选择图片出现错误，请检查相关权限。");
    }
    );
  }

  //将获取到的图片或者相机拍摄的图片进行另存为，用于后期图片的上传使用
  copyFileToLocalDir(namePath, currentName, newFileName) {
    this.file.copyFile(namePath, currentName, cordova.file.dataDirectory, newFileName).then(sucess => {
      this.lastImage = newFileName;
    }, error => {
      super.showToast(this.toastCtrl, "存储图片到本地图库出现错误。");
    });
  }

  //为文件生成一个新的文件名
  createFileName() {
    var d = new Date(),
      n = d.getTime(),
      newFileName = n + ",jpg"; //拼接文件名
    return newFileName;
  }

  //处理图片的路径为可以上传的路径
  public pathForImage(img) {
    if (img === null) {
      return '';
    }
    else {
      //https://ionicframework.com/docs/wkwebview/
      return normalizeURL(cordova.file.dataDirectory + img);//normalizeURL 重写file路径，适配ios11
    }
  }

  uploadImage() {
    var url = '';
    var targetPath = this.pathForImage(this.lastImage);
    var filename = this.userId + ".jpg" //定义上传后的文件名
    //上传的参数
    var options = {
      fileKey: "file",
      fileName: filename,
      chunkedMode: false,
      mimeType: "multipart/form-data",
      params: { 'fileName': filename, 'userid': this.userId }
    };

    const fileTransfer: TransferObject = this.transfer.create();

    var loading = super.showLoading(this.loadingCtrl, "上传中...");

    //开始正式上传
    fileTransfer.upload(targetPath, url, options).then(data => {
      loading.dismiss();
      super.showToast(this.toastCtrl, "图片上传成功。");
      //用户看清弹窗提示后进行页面的关闭
      setTimeout(() => {
        this.viewCtrl.dismiss();
      }, 3000);
    }, err => {
      loading.dismiss();
      super.showToast(this.toastCtrl, "图片上传发生错误，请重试。");
    });
  }
}