Add image to listview from Gallery in Flutter/dart - flutter

Question

This is currently what I have achived,
#override
Widget build(BuildContext context) {
_height = MediaQuery.of(context).size.height;
return Scaffold([![enter image description here][1]][1]
resizeToAvoidBottomInset: false,
extendBodyBehindAppBar: true,
appBar: AppBar(
leading: GestureDetector(
child: Image.asset('graphics/back_arrow.png'),
onTap: () {
Get.back();
},
),
backgroundColor: Colors.transparent,
elevation: 0,
title: Text(
'Ask The Internet',
style: GoogleFonts.montserrat(
fontSize: 20,
fontStyle: FontStyle.normal,
fontWeight: FontWeight.bold,
color: Colors.white),
),
),
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("graphics/login.png"),
fit: BoxFit.cover,
),
),
child: Column(
children: [
Container(
width: double.infinity,
height: _height * 0.15,
),
Container(
padding:
EdgeInsets.only(top: 64, left: 16, right: 16, bottom: 16),
height: _height * 0.85,
width: double.infinity,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(64),
topRight: Radius.circular(64),
),
),
child: SingleChildScrollView(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Align(
alignment: Alignment.center,
child: Text(
'Ask The Internet',
style: GoogleFonts.montserrat(
fontSize: 16,
fontStyle: FontStyle.normal,
fontWeight: FontWeight.w600,
color: loginPageTitleColor),
),
),
SizedBox(
height: _height * 0.04,
),
Text(
'Upload Content for UP',
style: GoogleFonts.montserrat(
fontSize: 14,
fontStyle: FontStyle.normal,
fontWeight: FontWeight.normal,
color: askInternetPageTitleColor),
),
SizedBox(
height: _height * 0.01,
),
Row(
children: [
GestureDetector(
child: Image.asset('graphics/add.png'),
onTap: () {
_pickImages();
},
),
],
),
Align(
alignment: Alignment.center,
child: Image.asset('graphics/divider.png')),
SizedBox(
height: _height * 0.04,
),
Text(
'Upload Content for DOWN',
style: GoogleFonts.montserrat(
fontSize: 14,
fontStyle: FontStyle.normal,
fontWeight: FontWeight.normal,
color: askInternetPageTitleColor),
),
SizedBox(
height: _height * 0.01,
),
Image.asset('graphics/add.png'),
Align(
alignment: Alignment.center,
child: Image.asset('graphics/divider.png')),
SizedBox(
height: _height * 0.06,
),
TextFieldInput(
titleText: 'Text up to 140 characters',
hintText: 'Enter Question',
inputType: TextInputType.visiblePassword,
textEditingController: controller.questionController,
titleTextStyle: GoogleFonts.montserrat(
fontSize: 15,
fontWeight: FontWeight.normal,
color: editProfivePageTitleColor),
),
SizedBox(
height: _height * 0.04,
),
Align(
alignment: Alignment.center,
child: Text(
'Ask The Community',
style: GoogleFonts.montserrat(
fontSize: 16,
fontStyle: FontStyle.normal,
fontWeight: FontWeight.w600,
color: loginPageTitleColor),
),
),
SizedBox(
height: _height * 0.04,
),
Text(
'Select The Community',
style: TextStyle(fontSize: 20, color: Colors.black38),
),
Obx(
() => DropdownButton<CommunityItem>(
isExpanded: true,
value: controller.item.value,
items:
controller.communityRows.map((CommunityItem value) {
return DropdownMenuItem<CommunityItem>(
value: value,
child: Text(value!.name!),
);
}).toList(),
onChanged: (value) {
controller.item.value = value!;
},
),
),
SizedBox(
height: _height * 0.04,
),
GestureDetector(
child: Container(
width: double.maxFinite,
height: 55,
decoration: BoxDecoration(
borderRadius: BorderRadius.all(
Radius.circular(4.0),
),
color: Colors.black,
image: DecorationImage(
image: AssetImage("graphics/btn.png"),
fit: BoxFit.cover),
),
child: Center(
child: Text(
"Save",
style: GoogleFonts.montserrat(
fontSize: 18,
fontWeight: FontWeight.bold,
color: Colors.white),
),
) // button text
),
onTap: () {
print("you clicked me");
},
),
],
),
),
),
],
),
),
);
}
I want when user click on plus icon he can add images from gallery, just like this.
I tried to use Listview builder but it was not prefect.