How to place a widget in specific position of a resizable page? [Flutter]-CodePudding

I'm working on a page where there are some fields like textfield and a slider. At the end of the page there must be a button for proceeding to next step which is wrapped in an Align to have a fixed position across pages.

On the other hand, the resizeToAvoidBottomInset attribute is true; so, when someone taps on a textfield the page resizes to keep textfield visible. The problem is that in case of tapping the textfield, the button moves upward to the middle of page.

Now, what I want, is a way to place the button in a fixed position while the page remains resizable.

here is the build's code:

Widget build(BuildContext context) {
    return MaterialApp(
      home: GestureDetector(
        onTap: () => FocusManager.instance.primaryFocus?.unfocus(),
        child: Scaffold(
          extendBodyBehindAppBar: true,
          resizeToAvoidBottomInset: true,
          body: Stack(
            children: [
              const Background(),
              getTopbar(),
              getBody(),
              getProceedButton()
            ],
          ),
        ),
      ),
    );
  }

here is an abstract version of getBody's function:

return Padding(
    padding: const EdgeInsets.only(top: topbarHeigthSmall),
    child: Container(
        height: MediaQuery.of(context).size.height - topbarHeigthSmall,
        child: Padding(
            padding: const EdgeInsets.only(right: 30, left: 30),
            child: SingleChildScrollView(
                child: Column(
                    children: [
                        //children of page like textfields and ... 
                    ],
                ),
            ),
        ),
    ),
);

and finally the code for button:

Widget getProceedButton() {
    return Align(
      alignment: const Alignment(0.0, 0.8),
      child: Container(...),
    );
}

Here is a screenshot before tapping a textfield: link to image

Here is another screenshot afterwards:

CodePudding user response：

just put your button widget inside of Positioned, like this:

Positioned(
          top:MediaQuery.of(context).size.height * 0.8,
              left: 0,
              right: 0,
              child: button(),);