Flutter: Outline input border

I was trying to build a border for my text field like:

return TextField(
  ...
 border: OutlineInputBorder(
  borderSide: BorderSide(
   color: Colors.red, 
    width: 5.0),
    )
  )
)

But it always return a black border with 1.0 as width. The only way that I found to change the color was to create a ThemeData where I specify the hint color, but I could not find a way to change my width.

What your looking for is - enabledBorder property of InputDecoration.

If you want to Change Border on focus use - focusedBorder

    TextField(
        decoration: new InputDecoration(
            focusedBorder: OutlineInputBorder(
                borderSide: BorderSide(color: Colors.greenAccent, width: 5.0),
            ),
            enabledBorder: OutlineInputBorder(
                borderSide: BorderSide(color: Colors.red, width: 5.0),
            ),
            hintText: 'Mobile Number',
        ),
    ),

For others coming here who just want a TextField with a border all around it:

TextField(
  decoration: InputDecoration(
    border: OutlineInputBorder(),
  ),
),

You can use Container to give border your text field. add the TextField as a child to a Container that has a BoxDecoration with border property:

  Container(
      margin: EdgeInsets.all(10),
      padding: EdgeInsets.all(10),
      decoration: BoxDecoration(
        color: Colors.white,
        border: Border.all(
            color: Colors.red,// set border color
            width: 3.0),   // set border width
        borderRadius: BorderRadius.all(
            Radius.circular(10.0)), // set rounded corner radius
      ),
      child: TextField(
        decoration: InputDecoration(
          hintText: 'Label text',
          border: InputBorder.none,
        ),
      ),
    )