How to change height of DropdownButton in flutter

Question

How can I change the height of a DropdownButton in flutter. I have tried to use Padding and SizedBox but none is realy working.

SizedBox just increases the container size while the DropdownButton is clamped to top left and therefore is not centered anymore. Padding is ignored or moves the content outside of the button.

I do not want to change the size of the dropdown overlay but the button itself.


build(BuildContext context) {
  return ThemeData(
    data: ThemeData(canvasColor: Colors.white),
    child: DropdownButton(
      items: _items.map((item) => DropdownMenuItem(child: Text(item), value: item)).toList(),
      isExpanded: true,
      selectedItemBuilder: (_) {
        return _items.map<Widget>((String lang) {
          return Center(
            widthFactor: 1,
            child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 12),
              child: Text(lang, style: TextStyle(color: Colors.black))
            ),
          );
        }).toList();
      }
    )
  )
}

menuMaxHeight: 300 this solves it – Afolayan Ademola Jul 29 '22 at 01:48 — Afolayan Ademola, Jul 29 '22 at 01:48

score 14 · Answer 1 · answered Sep 10 '20 at 15:50

Wrap it in a Container, give a height, width as per your need and set isExpanded true in DropDownButton. Also change dropdownbutton text font size as per your need.

Container(
  height: 50.0,
  width: 200.0,
  child: DropdownButton(
           value: dropdownValue,
           icon: Icon(Icons.arrow_downward),
           iconSize: 24,
           elevation: 16,
           isExpanded: true,
           style: TextStyle(color: Colors.deepPurple, fontSize: 20.0),
           underline: Container(
             height: 2,
             color: Colors.deepPurpleAccent,
           ),
           onChanged: (String newValue) {
             setState(() {
               dropdownValue = newValue;
             });
           },
           items: <String>['One', 'Two', 'Free', 'Four']
               .map<DropdownMenuItem<String>>((String value) {
             return DropdownMenuItem<String>(
               value: value,
               child: Text(value),
             );
           }).toList(),
         )
)

End product should look something like this,

score 8 · Answer 2 · edited Sep 10 '20 at 15:51

Looks like the 'itemHeight' property for the DropdownButton class should do the trick. I tried it and it increased the height of my DropdownButton.

Here is some sample code I have from a previous project using the itemHeight:

DropdownButton<String>(
      itemHeight: 100.0,
      value: selectedCurrency,
      items: dropdownItems,
      onChanged: (value) {
        setState(() {
          selectedCurrency = value;
          getData();
        });
      },
    );

Note: Just make sure the value you provide isn't less than 48.0, since it will give an error.

Docs: itemHeight property: https://api.flutter.dev/flutter/material/DropdownButton/itemHeight.html

Minimum itemHeight defined by 'kMinInteractiveDimension': https://api.flutter.dev/flutter/material/kMinInteractiveDimension-constant.html

score 7 · Answer 3 · answered Aug 22 '21 at 03:13

7

itemHeight: null,

You just need to leave the itemHeight with the null value.

It will make the height of the DropdownButton with the menu item's intrinsic height.

answered Aug 22 '21 at 03:13

BOM Nguyen

111
1
2

score 5 · Answer 4 · answered Mar 03 '21 at 10:21

5

Use SizedBox Widget

SizedBox(
      height: 30,
      child:DropdownButton<String>(
      value: selectedCurrency,
      items: dropdownItems,
      onChanged: (value) {},
    ))

answered Mar 03 '21 at 10:21

Bholendra Singh

980
7
14

score 3 · Answer 5 · answered Jun 23 '22 at 13:32

3

You need to use menuMaxHeight property of DropdownButton Widget.

child: DropdownButton(
 menuMaxHeight: 500.0,
 value: '1',
 items: setTotalPages(),
 onChanged: (String? newValue) {
 setState(() {
 dropdownvalue = newValue!;
 });
},

)

answered Jun 23 '22 at 13:32

Yunus Yerli

89
5

score 0 · Answer 6 · answered May 12 '22 at 03:13

The easiest of all methods is using DropDownButton2 which is built over DropDownButton

And just change the buttonHeight attribute

Not just buttonHeight , you can even change itemHeight , buttonwidth and many more customize

String? selectedValue;
List<String> items = [
  'Item1',
  'Item2',
  'Item3',
  'Item4',
];

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: Center(
      child: DropdownButtonHideUnderline(
        child: DropdownButton2(,
          items: items
                  .map((item) =>
                  DropdownMenuItem<String>(
                    value: item,
                    child: Text(
                      item,
                     ),
                  ))
                  .toList(),
          value: selectedValue,
          onChanged: (value) {
            setState(() {
            });
          },
          buttonHeight: 40,
          buttonWidth: 140,
          itemHeight: 40,
        ),
      ),
    ),
  );
}

checkout : DropDownButton2 for more examples.

Hope it helps !!

score 0 · Answer 7 · answered Jul 29 '22 at 01:49

0

Add this property menuMaxHeight: 200, to DropdownButton

answered Jul 29 '22 at 01:49

Afolayan Ademola

137
1
6

How to change height of DropdownButton in flutter

7 Answers7