How to get AppBar height in Flutter?

Question

How can I get the height of an AppBar in Flutter?
I am using the MarialApp Widget (\'package:flutter/material.dart\').

I have the height of my C

Answer 1

Use preferred size

//defined as
Size preferredSize

preferred size is a size whose height is the sum of kToolbarHeight and the bottom widget's preferred height.

Scaffold uses this size to set its app bar's height.

It is defined like below in app bar class which implement PreferredSizeWidget

 preferredSize = new Size.fromHeight(kToolbarHeight + (bottom?.preferredSize?.height ?? 0.0))

a link for example ...

https://github.com/flutter/flutter/blob/master/packages/flutter/lib/src/material/app_bar.dart

Answer 2

This is not an ideal way, I think, but it will work.

Firstly declare the AppBar widget that you will use in your Scaffold.

Widget demoPage() {
  AppBar appBar = AppBar(
    title: Text('Demo'),
  );
  return Scaffold(
    appBar: appBar,
    body: /*
    page body
    */,
  );
}

Now you can get the height of your appBar using its preferredSized:

double height = appBar.preferredSize.height;

You can use this height to reduce from the screen height.

final double height = MediaQuery.of(context).size.height;

Answer 3

you can use this :

var height = AppBar().preferredSize.height;

this way is very sample and easy

Answer 4

There is a constant for the normal toolbar height: kToolbarHeight