如何在 flutter 中将 Blob 转换为图像

Question

i want to display an image stored in mysql database the problem is that i can't convert the blob format into a Uint8list; i searched and found soulitions but none of them works Grab the blob from JSON:

var blob = yourJSONMapHere['yourJSONKeyHere'];

var image = BASE64.decode(blob); // image is a Uint8List

Now, use image in a Image.memory

new Container( child: new Image.memory(image));

this soulition didn't work because base64.decode need a string source not a blob file to convert

Answer 1

Don't know if it is relatable to this particular case but had similar issue with Cloud Firestore.

Created blob for storing in this way:

Blob myBlob = Blob(await audioFile.readAsBytes());

saved to Firestore in one field as usual Then tried to read it back and couldn't figure it out how to get Uint8List from blob I get back from Firestore.

my solution:

//extract blob from field of Firestore document
Blob audioBlob = audioDocFromDb.get("fieldName");

//use .bytes on blob from this source
//package:cloud_firestore_platform_interface/src/blob.dart
Uint8List audioBytes = audioBlob.bytes;

this worked for me. In my case I was packing up recorded audio and trying to play it back.

Answer 2

I had this problem too, i know the solution now, after many attempts: Dont forget to upvote!

Uint8List image = Uint8List.fromList(blob.toBytes());

Image.memory(image);

Answer 3

This function has always saved me for getting bytes from a file that is uploaded to a URL.

import 'package:http/http.dart' as http;

// urlImageBlob is the URL where our file is hosted.

Uint8List fileBytes = await http.readBytes(Uri.parse(urlImageBlob));

// Display if are image. Image.memory(fileBytes);