无法从文件 URI 显示图像，离子框架

Question

我正在尝试显示从相机拍摄的图像并将其显示到视图中。我在许多网站上搜索过这个答案，但没有任何效果。我尝试过 DomSanitizer、Base64 甚至照片库，但从它们返回的图像没有显示。

我的 home.ts 文件是

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { Camera, CameraOptions } from '@ionic-native/camera';
import { DomSanitizer } from '@angular/platform-browser';

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

  myPhoto:any;
  image;
  constructor(public navCtrl: NavController, private camera: Camera, public DomSanitizer: DomSanitizer) {

  }

  takePhoto(){
    const options: CameraOptions = {
      quality: 100,
      targetHeight: 320,
      targetWidth: 320,
      destinationType: this.camera.DestinationType.FILE_URI,
      sourceType: this.camera.PictureSourceType.CAMERA,
      encodingType: this.camera.EncodingType.JPEG,
      mediaType: this.camera.MediaType.PICTURE
    }

    this.camera.getPicture(options).then((imageData) => {
     // imageData is either a base64 encoded string or a file URI
     // If it's base64 (DATA_URL):
     this.myPhoto = 'data:image/jpeg;base64,' + imageData;
     this.image = imageData;
     console.log(this.myPhoto);
     alert(this.myPhoto);
    }, (err) => {
     // Handle error
    });
  }
}

这是我的 home.html 代码

<ion-header>
  <ion-navbar>
    <ion-title>
      Ionic Blank
    </ion-title>
  </ion-navbar>
</ion-header>

<ion-content padding>
  <button ion-button (click)="takePhoto()" >Take Photo</button>

  <!-- <img src="{{myPhoto}}"/> -->
  <!-- <img src="{{image}}"/> -->
  <!-- <img [src]="DomSanitizer.bypassSecurityTrustUrl(myPhoto)"/> -->
  <!-- <img data-ng-src="{{myPhoto}}"/> -->
  <img src="data:image/jpeg;base64,file:///storage/sdcard0/Android/data/io.ionic.starter/cache/1533211220154.jpg"/>
</ion-content>

这里的注释代码是我尝试过但没有成功。

Answer 1

按照以下方式修改你的home.ts，

  private openGallery(): void {
    let cameraOptions = {
      sourceType: this.camera.PictureSourceType.PHOTOLIBRARY,
      destinationType: this.camera.DestinationType.FILE_URI,
      quality: 100,
      targetWidth: 1000,
      targetHeight: 1000,
      encodingType: this.camera.EncodingType.JPEG,
      correctOrientation: true
    }

    this.camera.getPicture(cameraOptions)
      .then(file_uri => this.imageSrc = file_uri,
      err => console.log(err));
  }

在您的 html 文件中，

<img [src]="imageSrc"/> 

Answer 2

在你的 ts 文件中使用这个函数

takePhoto(){
    const options: CameraOptions = {
      quality: 100,
      targetHeight: 320,
      targetWidth: 320,
      destinationType: this.camera.DestinationType.DATA_URL,
      sourceType: this.camera.PictureSourceType.CAMERA,
      encodingType: this.camera.EncodingType.JPEG,
      mediaType: this.camera.MediaType.PICTURE
    }

    this.camera.getPicture(options).then((imageData) => {
      // imageData is either a base64 encoded string or a file URI
      // If it's base64 (DATA_URL):
      this.myPhoto = 'data:image/jpeg;base64,' + imageData;
      this.image = imageData;
      console.log(this.myPhoto);
    }, (err) => {
      // Handle error
    });
  }

在你的 html 中使用它

<img [src]="myPhoto"/>

Answer 3

我使用了文件插件及其方法 readAsDataURL。它对我来说很好。希望它会帮助那里的人:)

const options: CameraOptions = {
      quality: 100,
      allowEdit: true,
      sourceType:  this.camera.PictureSourceType.CAMERA ,
      saveToPhotoAlbum: true,
      correctOrientation: true,
      encodingType: this.camera.EncodingType.JPEG,
      destinationType: this.camera.DestinationType.FILE_URI
    }

this.camera.getPicture(options).then((imageData) => {

    //imageData will hold the full file path so we need to extract filename and path using file plugin 
     var filename = imageData.substring(imageData.lastIndexOf('/')+1);
     var path =  imageData.substring(0,imageData.lastIndexOf('/')+1);
    //then use it in the readAsDataURL method of cordova file plugin
    //this.file is declared in constructor file :File
         this.file.readAsDataURL(path, filename).then(res=>{
           item.pic = res;
         });
}, (err) => {
 alert(err);
});

link for ionic cordova file plugin

Answer 4

终于找到解决办法了：

在组件中：

takePhoto(){
    const options: CameraOptions = {
      quality: 100,
      targetHeight: 320,
      targetWidth: 320,
      destinationType: this.camera.DestinationType.FILE_URI,
      sourceType: this.camera.PictureSourceType.CAMERA,
      encodingType: this.camera.EncodingType.JPEG,
      mediaType: this.camera.MediaType.PICTURE
    }

    this.camera.getPicture(options).then((imgFileUri) => {
     this.myImg = (<any>window).Ionic.WebView.convertFileSrc(imgFileUri);
    }, (err) => {
     console.log(err);
    });
  }

在 html 中：

<img [src]="myImg" />

注意： cordova-plugin-ionic-webview >= 4