rename method Null safety

Future<File> rename(
  1. String newPath

Renames this file.

Returns a Future<File> that completes with a File for the renamed file.

If newPath is a relative path, it is resolved against the current working directory (Directory.current). This means that simply changing the name of a file, but keeping it the original directory, requires creating a new complete path with the new name at the end. Example:

Future<File> changeFileNameOnly(File file, String newFileName) {
  var path = file.path;
  var lastSeparator = path.lastIndexOf(Platform.pathSeparator);
  var newPath = path.substring(0, lastSeparator + 1) + newFileName;
  return file.rename(newPath);

On some platforms, a rename operation cannot move a file between different file systems. If that is the case, instead copy the file to the new location and then remove the original.

If newPath identifies an existing file, that file is removed first. If newPath identifies an existing directory, the operation fails and the future completes with an exception.


Future<File> rename(String newPath);