title: How to remove the second appbar in Flutter
body: <p>I am trying to build a demo chat app with <code>Flutter</code>. After my main screen, I am using <code>Navigator.push</code> to go to the details screen. 
  Screenshot of problem: </p>
  
  <p><a href="https://i.stack.imgur.com/7YnbW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7YnbW.png" alt="problem screenshot"></a> </p>
  
  <p>build method of 1st screen: </p>
  
  <pre><code>@override
   Widget build(BuildContext context) {
  return Scaffold(
      appBar: AppBar(
        title: const Text("Chat Thread App"),
        actions: &lt;Widget&gt;[
          IconButton(
            icon: Icon(Icons.settings),
            onPressed: () {
              Navigator.pushNamed(context, '/settings');
            },
          )
        ],
      ),
      body: isLoading
          ? Center(
              child: CircularProgressIndicator(),
            )
          : new ChatThreadListCard(messageThreads: _messageThreadLists, user: _user,),
  );
  }
  </code></pre>
  
  <p>code of <code>Navigator.push</code> method: </p>
  
  <pre><code>Navigator.push(context, MaterialPageRoute(
          builder: (context) =&gt; ChatDetailsScreen(threadModel: new ThreadModel(
                user.id, 
                user.fullName, 
                user.pic, 
                "otherId", 
                "otherName", 
                "otherPic", 
                post.threadId
              )
            ),
        ),);
  </code></pre>
  
  <p>build method of 2nd screen, where the problem is produced:</p>
  
  <pre><code>return Scaffold(
    appBar: AppBar(
      title: Text("Chat demo"),
    ),
    body: WillPopScope(
      child: isLoading
          ? Center(
              child: CircularProgressIndicator(),
            )
          : Stack(
              alignment: AlignmentDirectional.bottomCenter,
              children: &lt;Widget&gt;[
                SizedBox(
                  width: 300,
                  height: 300,
                ),
                Column(
                  children: &lt;Widget&gt;[
                    buildChat(),
                    buildInput(),
                  ],
                )
              ],
            ),
      onWillPop: onBackPress,
    ),
  );
  </code></pre>