Remove underline from DropdownButtonFormField - dart

Question

How can I remove the underline from DropdownButtonFormField (check photo below), I have tried various combinations of options with InputDecortaion couldn't find any way.
SizedBox(
width: 100.0,
child: DropdownButtonFormField<int>(
decoration: InputDecoration(
border: UnderlineInputBorder(
borderSide:
BorderSide(color: Colors.white))),
value: 2,
items: <DropdownMenuItem<int>>[
DropdownMenuItem<int>(
value: 1,
child: Text("Owner"),
),
DropdownMenuItem<int>(
value: 2,
child: Text("Member"),
),
],
),

Answer 1

Just wrap DropdownButton inside DropdownButtonHideUnderline like this :
new DropdownButtonHideUnderline(
child: DropdownButton()
)

Answer 2

Setting the underline property to SizedBox() makes it invisible too:
...
DropdownButton(
underline: SizedBox(),
...

Answer 3

One way of Doing it :
In your Code - change decoration: InputDecoration to decoration: InputDecoration.collapsed
body: SizedBox(
width: 100.0,
child: DropdownButtonFormField<int>(
decoration: InputDecoration.collapsed(hintText: ''),
value: 2,
...
OR
In your Code - instead of border Use enabledBorder: UnderlineInputBorder
DropdownButtonFormField<int>(
decoration: InputDecoration(
enabledBorder: UnderlineInputBorder(
borderSide: BorderSide(color: Colors.white))),
value: 2,
items: <DropdownMenuItem<int>>[
....

Answer 4

The proper/clean solution nowadays is to use InputBorder.none:
DropdownButtonFormField<int>(
decoration: InputDecoration(
enabledBorder: InputBorder.none,
...
),
...
)
You might also want to set border, focusedBorder, errorBorder, and disabledBorder to InputBorder.none if you want to avoid the border from showing in all cases.

Answer 5

underline can take a widget so, you just have assigned it an empty Container, or a SizedBox.shrink()
underline:Container(),
-- or --
underline:SizedBox.shrink(),
Example :
child: DropdownButton<String>(
// Just have to assign to a empty Container
underline:Container(),
value: dropdownValue,
icon: Icon(Icons.keyboard_arrow_down),
iconSize: 24,
elevation: 16,
onChanged: (String newValue) {
setState(() {
dropdownValue = newValue;
});
},
items:[
deptList[0].dept,
deptList[1].dept,
deptList[2].dept,
deptList[3].dept,
].map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(value),
);
}).toList(),
)

Answer 6

Add underline: Container() to your settings like this:
SizedBox(
...
underline: Container(),
),

Answer 7

According to this [Flutter Doc] You can do like this. Simply create an object of DropdownButtonHideUnderline class and pass your current implementation of the DropdownButton as the child of DropdownButtonHideUnderline. Thts it ;)
DropdownButtonHideUnderline(
child: new DropdownButton<String>(
......
),
),

Answer 8

As of now, DropdownButtonFormField doesn't support DropdownButtonHideUnderline.
Although it uses it under the hood to remove the underline from DropdownButton but then applies it's own decoration on top of that
Setting border to InputBorder.none will do the job
DropdownButtonFormField<String>(
decoration: InputDecoration(border: InputBorder.none)
)
If you want the border to appear on error you can use
InputDecoration(
border: InputBorder.none,
errorBorder: UnderlineInputBorder(
borderSide: BorderSide(color: Colors.red),
),
),

Answer 9

You can change underline property to blank or null widget it will work like charm check the below property
underline: widget or SizedBox(),
Ex:-
DropdownButton(
icon: Icon(Icons.more_vert),
isExpanded: true,
value: dropValue,
underline: widget or SizedBox(),

Answer 10

use
DropdownButton<String>(
hint: Text("Status"),
value: 'Text Default',
isExpanded: true,
iconSize: 30,
underline: Container(
height: 1.0,
decoration: const BoxDecoration(
border: Border(bottom: BorderSide(color: Colors.transparent, width: 0.0))
),
),
...

Answer 11

Easy Way to do it
DropdownButtonFormField<String>(
decoration: InputDecoration(
enabledBorder: UnderlineInputBorder(
borderSide: BorderSide(color: Colors.transparent),
),
),
...
)

Answer 12

DropdownButtonHideUnderline(
child: DropdownButton(
isExpanded: true,
hint: Padding(
padding: const EdgeInsets.all(8.0),
child: Text("Select State"),
),
style: MyStyle().getTextStyle("x1black"),
items: <String>[
'Messaging',
'Chating',
'No Longer Interested',
'Document Request'
].map((String value) {
return new DropdownMenuItem<String>(
value: value,
child: new Text(value),
);
}).toList(),
onChanged: (_) {},
),
),

Answer 13

Underline takes a Widget. Pass it a blank widget, like below.
DropdownButton<T>(
value: value,
underline: SizeBox(), // Empty box will remove underline
)

Answer 14

You could try the following code:
decoration: InputDecoration(
border: InputBorder.none,
)
To disable every border on the width, set InputBorder.none for border attribute. Or if you prefer to disable only the border when dropdown is enable, set for enabledBorder.

Answer 15

if DropdownButtonFormField text get trim due to outline border then use this code:
DropdownButtonFormField<String>(
decoration: InputDecoration(
enabledBorder: UnderlineInputBorder(
borderSide: BorderSide(color: Colors.white)),
isDense: true,)

Answer 16

DropdownButtonHideUnderline(
child: ButtonTheme(
alignedDropdown: false,
splashColor: Colors.grey,
child: DropdownButton<String>(
value: _myPargna,
iconSize: 25,
icon: Icon(Icons.arrow_drop_down),
style:
TextStyle(fontSize: 18, color: Color(0xFF1f193d)),
hint: Row(
children: [
SizedBox(width: 11),
Text(
'Select Province',
style: TextStyle(color: Colors.grey),
),
],
),
onChanged: (String newValue) {
setState(() {
_myPargna = newValue;
});
},
items: items.map((String items) {
return DropdownMenuItem(
child: Row(
children: [
SizedBox(width: 12),
Text(
items,
style: TextStyle(color: Colors.black),
),
],
),
value: items,
);
}).toList(),
),
),
),

Answer 17

You can just Do this
decoration: const InputDecoration(
// enabledBorder: InputBorder.none,
// disabledBorder: InputBorder.none,
// focusedBorder: InputBorder.none,
// errorBorder: InputBorder.none,
border: InputBorder.none,
),

Answer 18

DropdownButtonFormField(
iconSize: 30,
decoration: InputDecoration(enabledBorder: InputBorder.none),
hint: Text(
"Select Duration",
style: TextStyle(fontSize: 20),
),
items: listDrop,
onChanged: (value) {
duration = value;
},
)

Answer 19

if you want just disable the border in all the case you can use :
DropdownButtonFormField(
validator: _validator,
decoration: InputDecoration(
border: InputBorder.none,
),
items: [],
onChanged: (value) {}),
),
if you want disable only when there is no error you can use this

Answer 20

decoration: InputDecoration(
errorBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.transparent)),
enabledBorder: OutlineInputBorder(
borderRadius: BorderRadius.circular(2.0),
borderSide: BorderSide(color: kLightBlackColor)),
),

Answer 21

This worked for me
DropdownButtonFormField<String>(decoration: InputDecoration(border: InputBorder.none),)