[flutter] How to change TextField's height and width?

How to customise TextField's width and height?

Wrap TextField in SizedBox for the width

I think you want to change the inner padding/margin of the TextField.

You can do that by adding isDense: true and contentPadding: EdgeInsets.all(8) properties as follow:

Container(
  padding: EdgeInsets.all(12),
  child: Column(
    children: <Widget>[
      TextField(
        decoration: InputDecoration(
          border: OutlineInputBorder(),
          labelText: 'Default TextField',
        ),
      ),
      SizedBox(height: 16,),
      TextField(
        decoration: InputDecoration(
          border: OutlineInputBorder(),
          labelText: 'Densed TextField',
          isDense: true,                      // Added this
        ),
      ),
      SizedBox(height: 16,),
      TextField(
        decoration: InputDecoration(
          border: OutlineInputBorder(),
          labelText: 'Even Densed TextFiled',
          isDense: true,                      // Added this
          contentPadding: EdgeInsets.all(8),  // Added this
        ),
      )
    ],
  ),
)

It will be displayed as:

You can simply wrap Text field widget in padding widget..... Like this,

Padding(
         padding: EdgeInsets.only(left: 5.0, right: 5.0),
          child: TextField(
            cursorColor: Colors.blue,

            decoration: InputDecoration(
                labelText: 'Email',
                hintText: '[email protected]',
                //labelStyle: textStyle,
              border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(5),
                  borderSide: BorderSide(width: 2, color: Colors.blue,)),
              focusedBorder: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(10),
                  borderSide: BorderSide(width: 2, color: Colors.green)),
                )

            ),
          ),

To increase the height of TextField Widget just make use of the maxLines: properties that comes with the widget. For Example: TextField( maxLines: 5 ) // it will increase the height and width of the Textfield.

TextField( minLines: 1, maxLines: 5, maxLengthEnforced: true)

You can try the margin property in the Container. Wrap the TextField inside a Container and adjust the margin property.

new Container(
  margin: const EdgeInsets.only(right: 10, left: 10),
  child: new TextField( 
    decoration: new InputDecoration(
      hintText: 'username',
      icon: new Icon(Icons.person)),
  )
),

int numLines = 0;

Container( height: numLines < 7 ? 148 * WidgetsConstant.height : numLines * WidgetsConstant.height * 24, child: TextFormField( controller: _bodyText, maxLines: numLines < 7 ? 148 : numLines, keyboardType: TextInputType.multiline, textInputAction: TextInputAction.newline,
onChanged: (String value) { setState(() { numLines = '\n'.allMatches(value).length + 1; }); }, ), ),

If you want to increase the height of TextFormField dynamically while typing the text in it. Set maxLines to null. Like

TextFormField(
          onSaved: (newText) {
            enteredTextEmail = newText;
          },

          obscureText: false,
          keyboardType: TextInputType.emailAddress,
          validator: validateName,
          maxLines: null,
          // style: style,
          decoration: InputDecoration(
              contentPadding: EdgeInsets.fromLTRB(5.0, 10.0, 5.0, 10.0),
              hintText: "Enter Question",
              labelText: "Enter Question",
              border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(10.0))),
        ),

If you use "suffixIcon" to collapse the height of the TextField add: suffixIconConstraints

TextField(
                    style: TextStyle(fontSize: r * 1.8, color: Colors.black87),
                    decoration: InputDecoration(
                      isDense: true,
                      contentPadding: EdgeInsets.symmetric(vertical: r * 1.6, horizontal: r * 1.6),
                      suffixIcon: Icon(Icons.search, color: Colors.black54),
                      suffixIconConstraints: BoxConstraints(minWidth: 32, minHeight: 32),
                    ),
                  )

use contentPadding, it will reduce the textbox or dropdown list height

InputDecorator(
                  decoration: InputDecoration(
                      errorStyle: TextStyle(
                          color: Colors.redAccent, fontSize: 16.0),
                      hintText: 'Please select expense',
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(1.0),
                      ),
                      contentPadding: EdgeInsets.all(8)),//Add this edge option
                  child: DropdownButton(
                    isExpanded: true,
                    isDense: true,
                    itemHeight: 50.0,

                    hint: Text(
                        'Please choose a location'), // Not necessary for Option 1
                    value: _selectedLocation,
                    onChanged: (newValue) {
                      setState(() {
                        _selectedLocation = newValue;
                      });
                    },
                    items: citys.map((location) {
                      return DropdownMenuItem(
                        child: new Text(location.name),
                        value: location.id,
                      );
                    }).toList(),
                  ),
                ),

Screenshot:

Widget _buildTextField() {
  final maxLines = 5;

  return Container(
    margin: EdgeInsets.all(12),
    height: maxLines * 24.0,
    child: TextField(
      maxLines: maxLines,
      decoration: InputDecoration(
        hintText: "Enter a message",
        fillColor: Colors.grey[300],
        filled: true,
      ),
    ),
  );
}