title: How to set dropdown selected item into TextFormField in Flutter
body: <p>I created dropdown in TextFormField in flutter, i successfully loaded list (bankDataList) into dropdown which is dynamic list. Data is showing into dropdown list. But i have a problem to assign
  &quot;value : _bankChoose&quot; into DropDownButton , it is not updating into TextFormField. I am using icon and text, please see screenshot.</p>
  <p><a href="https://i.stack.imgur.com/bbxSs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bbxSs.png" alt="screenshot" /></a></p>
  <pre><code>  String _bankChoose;
  
     List&lt;BankListDataModel&gt; bankDataList;
  
        Container(
                    margin: EdgeInsets.only(left: 15, top: 10, right: 15),
                      child: FormField&lt;String&gt;(
                        builder: (FormFieldState&lt;String&gt; state) {
                          return InputDecorator(
                            decoration: InputDecoration(
                                contentPadding:
                                    EdgeInsets.fromLTRB(12, 10, 20, 20),
                                // labelText: &quot;hi&quot;,
                                // labelStyle: textStyle,
                                // labelText: _dropdownValue == null
                                //     ? 'Where are you from'
                                //     : 'From',
                                errorText: _errorBank,
                                errorStyle: TextStyle(
                                    color: Colors.redAccent, fontSize: 16.0),
                                border: OutlineInputBorder(
                                    borderRadius:
                                        BorderRadius.circular(10.0))),
                            child: DropdownButtonHideUnderline(
                              child: DropdownButton&lt;BankListDataModel&gt;(
                                style: TextStyle(
                                  fontSize: 16,
                                  color: text_gray_color,
                                  fontFamily: &quot;verdana_regular&quot;,
                                ),
                                hint: Text(
                                  &quot;Select Bank&quot;,
                                  style: TextStyle(
                                    color: text_gray_color,
                                    fontSize: 16,
                                    fontFamily: &quot;verdana_regular&quot;,
                                  ),
                                ),
                                value: _bankChoose,
                                isExpanded: true,
                                isDense: true,
                                onChanged: (BankListDataModel newValue) {
                                  setState(() {
                                    _bankChoose = newValue.bank_name;
                                  });
                                },
                                items: bankDataList
                                    .map&lt;DropdownMenuItem&lt;BankListDataModel&gt;&gt;(
                                        (BankListDataModel valueItem) {
                                  return DropdownMenuItem(
                                    value: valueItem,
                                    child: Row(
                                      // mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                      children: [
                                        new CircleAvatar(
                                          backgroundImage: new NetworkImage(
                                              valueItem.bank_logo),
                                        ),
                                        // Icon(valueItem.bank_logo),
                                        SizedBox(
                                          width: 15,
                                        ),
                                        Text(valueItem.bank_name),
                                      ],
                                    ),
                                  );
                                }).toList(),
                              ),
                            ),
                          );
                        },
                      ),
                    ),
  </code></pre>