How to print to log in Flutter?

Question

I wanted to print a log statement onto any LogCat console (Verbose, Debug, etc) but I can't seem to find a way to do it.

The print() or debugPrint() doesn't seem to work, or better yet should I say I don't know where they are printing.

Also, for some reason, the LogCat console is saying "No connected devices" and "No debuggable process" even though I have the emulator running in background and the files are executing on the emulator perfectly.

Solution

Based on Flutter Doc, the logging view displays events from the Dart runtime, application frameworks (like Flutter), and application-level logging events.By default, the logging view shows:

• Garbage collection events from the Dart runtime
• Flutter framework events, like frame creation events
• stdout and stderr from applications
• Custom logging events from applications

Refer the Debugging Flutter Applications Programmatically Doc. You can use:

stderr.writeln('print me');

Or

import 'dart:developer' as developer;

void main() {
  developer.log('log me', name: 'my.app.category');

  developer.log('log me 1', name: 'my.other.category');
  developer.log('log me 2', name: 'my.other.category');
}

Or

import 'dart:convert';
import 'dart:developer' as developer;

void main() {
  var myCustomObject = ...;

  developer.log(
    'log me',
    name: 'my.app.category',
    error: jsonEncode(myCustomObject),
  );
}

to log from your app.

Comments

[Hitesh Sahu]

I have created a logger for flutter: stackoverflow.com/a/68595809/2252113. feel free to use it.