How to make a widget fill remaining space in a Column

In Android, we can do the following to make ImageView to fill as much space as possible depending on the size of the TextView.

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_weight="1"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</LinearLayout>

How do we achieve this in Flutter? Assume I need to make Datetime(green) to fill as much as possible.

new Column(
	children: <Widget>[
		new Text('Title',
			style: new TextStyle(fontWeight: FontWeight.bold)
		),
		new Text('Datetime',
			style: new TextStyle(color: Colors.grey)
		),
	],
)

Not 100% sure but I think you mean this. The Expanded widget expands to the space it can use. Althought I think it behaves a bit differently in a Row or Column.

new Column(
children: <Widget>[
    new Text('Title',
        style: new TextStyle(fontWeight: FontWeight.bold)
    ),
    new Expanded(
        child: new Text('Datetime',
             style: new TextStyle(color: Colors.grey)
        ),
    ),
],
)

You can use:

1. Expanded with Align to position child

    Column(
      children: [
        FlutterLogo(),
        Expanded( // add this
          child: Align(
            alignment: Alignment.bottomCenter,
            child: FlutterLogo(),
          ),
        ),
      ],
    )
   

2. Spacer

    Column(
      children: [
        FlutterLogo(),
        Spacer(), // add this
        FlutterLogo(),
      ],
    )
   

3. mainAxisAlignment

    Column(
      mainAxisAlignment: MainAxisAlignment.spaceBetween, // add this
      children: [
        FlutterLogo(colors: Colors.orange),
        FlutterLogo(colors: Colors.blue),
      ],
    )
   

If you need just to add blank space, use Spacer()

new Column(
children: <Widget>[
    new Text('Title',
        style: new TextStyle(fontWeight: FontWeight.bold)
    ),
    new Text('Datetime',
        style: new TextStyle(color: Colors.grey)
    ),
    Spacer(),
],

Flexible(
  child: Column(
    mainAxisAlignment:mainAxisAlignment.spacebetween,
    children: <Widget>[
        new Text('Title',
            style: new TextStyle(fontWeight: FontWeight.bold)
        ),
        new Text('Datetime',
            style: new TextStyle(color: Colors.grey)
        ),
  ],
)