title: Remove Flutter TabBar bottom border
body: <p>I'm trying to create a custom TabBar using PreferredSize, but I can't meld the color of the TabBar with my body, there seems to be a border between the TabBar and the body. The picture below will show you clearly what I'm trying to accomplish.</p>
  
  <p><a href="https://i.stack.imgur.com/SLxPY.png" rel="noreferrer"><img src="https://i.stack.imgur.com/SLxPY.png" alt="enter image description here"></a></p>
  
  <p>I have tried to create a border with the same color as the body with large width, but it doesn't seems to work. Here is my code:</p>
  
  <pre><code>  Widget _buildAppBar(context) {
  return AppBar(
    title: Text(title),
    elevation: 0,
    flexibleSpace: Image.asset(
      'images/motif_batik_01.jpg',
      fit: BoxFit.cover,
      width: 1200,
    ),
    bottom: _buildTabBar(context)
  );
  </code></pre>
  
  <p>}</p>
  
  <pre><code>  Widget _buildTabBar(context) {
  return PreferredSize(
    preferredSize: Size.fromHeight(100.0),
    child: Container(
      decoration: BoxDecoration(
        color: Theme.of(context).backgroundColor,
        borderRadius: BorderRadius.only(
          topLeft: Radius.circular(50),
          topRight: Radius.circular(50),
        ),
      ),
      padding: EdgeInsets.only(
        top: 50,
        left: 20,
        right: 20,
      ),
      height: 100,
      child: TabBar(
        indicator: BoxDecoration(
          color: Colors.orange, borderRadius: BorderRadius.circular(20)
        ),
        labelStyle: TextStyle(color: Colors.white),
        unselectedLabelColor: Colors.orange,
        tabs: &lt;Widget&gt;[
          Tab(child: Text('A', style: TextStyle(fontSize: 18.0))),
          Tab(child: Text('B', style: TextStyle(fontSize: 18.0))),
        ],
      ),
    )
  );
  </code></pre>
  
  <p>}</p>
  
  <p>Edit Notes: I figured out that if my 'preferedSize' is a multiplication of 40.0 (40.0, 80.0) the line disappears, could it be a bug in the flutter itself?</p>