Flutter Expansion Tile — Header Color Change, and Trailing Animated Arrow Color Change

问题

I have used the Expansion Tile to generate a Expansion List View. I'm facing some customization issues in Expansion Tile Header.

Below is my code.

ExpansionTile(           
    title: Container(
        child: Text(
            getCategory(i),
            style: TextStyle(
            color: Colors.white,
            ),
        ),
        color: Colors.black
    ),

    children: <Widget>[
        new Container(
            height: 60.0,
            margin: const EdgeInsets.only(top:10.0, left: 10.0, right:10.0, bottom: 10.0),
            decoration: BoxDecoration(                    
            color: Colors.blue,
            borderRadius: new BorderRadius.all(  Radius.circular(5.0) ),
            ),
        ),
        new Container(
            height: 60.0,
            margin: const EdgeInsets.only(top:10.0, left: 10.0, right:10.0, bottom: 0.0),
            decoration: BoxDecoration(                    
            color: Colors.green,
            borderRadius: new BorderRadius.all(  Radius.circular(5.0) ),
            ),
        )
    ],
    backgroundColor: Colors.white,
)

I'm getting below result.

What I'm expecting to have is below.

If anyone know a workaround to customize the header color, please advice.

回答1:

If you check the source code of the ExpansionTitle , you will notice that the header item is a ListTile , so you can't change the background because it hasn't a parent with a color property. I modified a little the class to support what you need.

Add this file to your project: https://gist.github.com/diegoveloper/02424eebd4d6e06ae649b31e4ebcf53c

And import like this way to avoid conflicts because the same name.

    import 'package:nameofyourapp/custom_expansion_tile.dart' as custom;

I put an alias 'custom' but you can change for any alias.

Usage:

    custom.ExpansionTile(
              headerBackgroundColor: Colors.black,
              iconColor: Colors.white,
              title: Container(
              ...

Remember, Flutter has a lot of Widgets out of the box, but If any of them don't fit what you need, you'll have to check the source code and create your own widget.

来源：https://stackoverflow.com/questions/53584678/flutter-expansion-tile-header-color-change-and-trailing-animated-arrow-color