dart - Add border to a Container with borderRadius in Flutter

Question

Container(
      child: Text(
          'This is a Container',
          textScaleFactor: 2,
          style: TextStyle(color: Colors.black),
      ),

      decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(10),
          color: Colors.white,
          border: Border(
              left: BorderSide(
                  color: Colors.green,
                  width: 3,
              ),
            ),
          ),
      height: 50,
     ),

This is supposed to show a rounded-edged container with a green left border 3px wide, and the child Text "This is a Container". However, it just shows a rounded-edged container with an invisible child and an invisible left border.

When I take out the borderRadius object, the child Text and the green left border is visible, but introducing it hides the left border and child Text again.

The major problem seems to be the custom left border, because using border: Border.all(width: 0) and borderRadius: BorderRadius.circular(10) makes the edges rounded as needed and also shows the child. But now I cant apply the green left border which is quite important in this particular setup.

So is there something I'm doing wrong, or is this a bug in flutter, or is it just something that is not allowed?

Thank you in advance.

Edit: The image below is the end result. The colors don't matter

question from:https://stackoverflow.com/questions/58350235/add-border-to-a-container-with-borderradius-in-flutter

Answer 1

It's not possible to add border: and borderRadius: at the same time, you'll get this error:

A borderRadius can only be given for uniform borders.

You can achieve what you want using the borderRadius: and a boxShadow: instead of border: like this:

boxShadow: [
  BoxShadow(color: Colors.green, spreadRadius: 3)
]

Your sample code would be like this:

Container(
  child: Text(
    'This is a Container',
    textScaleFactor: 2,
    style: TextStyle(color: Colors.black),
  ),
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(10),
    color: Colors.white,
    boxShadow: [
      BoxShadow(color: Colors.green, spreadRadius: 3),
    ],
  ),
  height: 50,
),

---

Edit: To achieve the example you now provided, you could do this:

Container(
  padding: EdgeInsets.only(left: 12.0),
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(10.0),
    color: Colors.green,
  ),
  height: 50,
  child: Container(
    decoration: BoxDecoration(
      borderRadius: BorderRadius.only(
          topRight: Radius.circular(10.0),
          bottomRight: Radius.circular(10.0)),
      color: Colors.white,
    ),
    child: Text(
      'This is a Container',
      textScaleFactor: 2,
      style: TextStyle(color: Colors.black),
    ),
  ),
),

Another solution:

Container(
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(10.0),
    color: Colors.white,
  ),
  height: 50,
  child: Row(
    mainAxisSize: MainAxisSize.min,
    children: <Widget>[
      Container(
        width: 12.0,
        decoration: BoxDecoration(
          borderRadius: BorderRadius.only(
              topLeft: Radius.circular(10.0),
              bottomLeft: Radius.circular(10.0)),
          color: Colors.green,
        ),
      ),
      Text(
        'This is a Container',
        textScaleFactor: 2,
        style: TextStyle(color: Colors.black),
      )
    ],
  ),
),