如何尊重列表中的回车（CR）<int> 在飞镖/颤振中进入字符串</int>

Question

I'm trying to convert List into String and show it in Text widget in flutter but it's not working as expected. Snippet below:

import 'dart:convert' show utf8;

List<int> val = [49, 46, 13, 104, 101, 108, 108, 111];
final decoded = utf8.decode(val);


....

Container(
    child: Text(decoded)
)

The text is showing:

1. hello

it should be:

1.
hello

Why it does not respect 13 (equivalent to carriage return)?

Any help is appreciated.

Thanks!

Answer 1

Try use LineSplitter to split the String into a list of lines and then combine the lines again using a StringBuffer :

import 'dart:convert' show utf8, LineSplitter;

void main() {
  final val = [49, 46, 13, 104, 101, 108, 108, 111];
  final lines = const LineSplitter().convert(utf8.decode(val));
  print(lines); // [1., hello]

  final message = lines
      .fold<StringBuffer>(
          StringBuffer(), (buffer, line) => buffer..writeln(line))
      .toString();
  print(message);
  // 1.
  // hello
}

This will ensure you are using the running platform supported line endings.

If it works it can be shorten down to:

import 'dart:convert' show utf8, LineSplitter;

void main() {
  List<int> val = [49, 46, 13, 104, 101, 108, 108, 111];

  final decoded = utf8.decode(val);
  print(decoded);

  final fixed = fixNewLines(decoded);
  print(fixed);
}

String fixNewLines(String text) => const LineSplitter()
    .convert(text)
    .fold<StringBuffer>(StringBuffer(), (buffer, line) => buffer..writeln(line))
    .toString();

Answer 2

For some reasons, Flutter looks for LF for line break and ignore CR. If you replace 13 (CR) by 10 (LF) it will works.

I don't know if this is a bug or it is platform dependent (tested on Android).