Flutter: Trying to bottom-center an item in a Column, but it keeps left-aligning

I'm trying to bottom-center a widget at the bottom of a Column, but it keeps aligning to the left.

return new Column(
  new Stack(
    new Positioned(
      bottom: 0.0, 
      new Center(
        new Container(),
      ),
    ),
  ),
); 

The existence of the Positioned forces the Container to the left, instead of centering. Removing the Positioned, however, puts the Container in the middle-center.

Solution 1:

Align is the way to go if you have only one child.

If you have more, consider doing something like this:

return new Column(
  crossAxisAlignment: CrossAxisAlignment.center,
  mainAxisSize: MainAxisSize.max,
  mainAxisAlignment: MainAxisAlignment.end,
  children: <Widget>[
      // Your elements here
  ],
);

Solution 2:

The easiest and the correct way to do it - use Spacer()

Example:

Column(
    children: [
      SomeWidgetOnTheTop(),
      Spacer(),
      SomeCenterredBottomWidget(),
    ],
);

Solution 3:

Expanded(
  child: Align(
    alignment: FractionalOffset.bottomCenter,
      child: Padding(
        padding: EdgeInsets.only(bottom: 10.0),
          child: //Your widget here,
    ),
  ),
),