How to convert asset image to File?

You can access the byte data via rootBundle. Then, you can save it to the device's temporary directory which is obtained by path_provider (you need to add it as a dependency).

import 'dart:async';
import 'dart:io';

import 'package:flutter/services.dart' show rootBundle;
import 'package:path_provider/path_provider.dart';

Future<File> getImageFileFromAssets(String path) async {
  final byteData = await rootBundle.load('assets/$path');

  final file = File('${(await getTemporaryDirectory()).path}/$path');
  await file.writeAsBytes(byteData.buffer.asUint8List(byteData.offsetInBytes, byteData.lengthInBytes));

  return file;
}

In your example, you would call this function like this:

File f = await getImageFileFromAssets('images/myImage.jpg');

For more information on writing the byte data, check out this answer.

You will need to await the Future and in order to do that, make the function async:

RaisedButton(
   onPressed: () async => showDialog(
     context: context,
     builder: (_) => Container(child: Image.file(await getImageFileFromAssets('images/myImage.jpg')))),
   child: Text('Show Image'));

Make use of flutter_absolute_path package.

flutter_absolute_path: ^1.0.6

In pubsec.yaml

To convert file path from this format :

“content://media/external/images/media/5275”

To

"/storage/emulated/0/DCIM/Camera/IMG_00124.jpg”

======

List <File> fileImageArray = [];
assetArray.forEach((imageAsset) async {
final filePath = await FlutterAbsolutePath.getAbsolutePath(imageAsset.identifier);

File tempFile = File(filePath);
if (tempFile.existsSync()) {
    fileImageArray.add(tempFile);
}

Get File from Asset without providing a path.

import 'package:path_provider/path_provider.dart';


Future<File> getImageFileFromAssets(Asset asset) async {
    final byteData = await asset.getByteData();

    final tempFile =
        File("${(await getTemporaryDirectory()).path}/${asset.name}");
    final file = await tempFile.writeAsBytes(
      byteData.buffer
          .asUint8List(byteData.offsetInBytes, byteData.lengthInBytes),
    );

    return file;
  }