React-Native使用从Blob转换而来的URL填充图像 [英] React-Native Populate image with URL that has been converted from a blob

问题描述

我正在尝试用URl填充图像

I am trying to populate an image with a URl

<Image source={{uri: this.state.imageURL}} style={styles.thumb} />

我使用提取API向服务器请求图片，并且它返回一个Blob.

I request the image from the server, using the fetch API, and it returns a blob.

然后我使用以下行将BLOB转换为URL:

I then convert the BLOB into a URL using the following line:

var imageURL = window.URL.createObjectURL(attachmentBLOB);

当我console.log()imageURL打印时:

When I console.log() the imageURL it prints:

blob:http%3A//localhost%3A8081/4ce24d92-0b7e-4350-9a18-83b74bed6f87

我没有收到任何错误或警告.图片只是不显示

I am getting no errors or warning. The image is just not displaying

我正在使用android模拟器.

I am using the android emulator.

请帮助.预先感谢！

推荐答案

解决方案

React-Native不支持Blob [ref: Git/React-Native ].为了使这项工作有效，我必须下载 react-native-fetch-blob 返回base64字符串.

Solution

React-Native does not support blobs [ref: Git/React-Native]. In order to get this working I had to download react-native-fetch-blob which returns a base64 string.

返回base64字符串的函数:

var RNFetchBlob = require('react-native-fetch-blob').default;

getImageAttachment: function(uri_attachment, mimetype_attachment) {

  return new Promise((RESOLVE, REJECT) => {

    // Fetch attachment
    RNFetchBlob.fetch('GET', config.apiRoot+'/app/'+uri_attachment)
      .then((response) => {

        let base64Str = response.data;
        var imageBase64 = 'data:'+mimetype_attachment+';base64,'+base64Str;
        // Return base64 image
        RESOLVE(imageBase64)
     })

   }).catch((error) => {
   // error handling
   console.log("Error: ", error)
 });
},

使用base64填充图像
然后，我使用返回的base64Image填充图像:

Populate Image with base64
I then populate the image withe the returned base64Image with:

<Image source={{uri: imageBase64}} style={styles.image} />

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