Automatically close the keyboard after GestureDetector onTap

UI/UX
1

I would input text into a TextField() and then use a GestureDetector to add the text. The problem was on the phone; it would not automatically close the keyboard. The simple solution was to call:

FocusManager.instance.primaryFocus?.unfocus();

My Code:

child: TextField(
                                      onChanged: (value) {
                                        // setState(() {
                                        //   _comment = value;
                                        // });
                                        _comment = value;
                                      },
                                      decoration: InputDecoration(
                                          filled: true,
                                          fillColor: const Color.fromARGB(
                                              255, 192, 192, 192),
                                          border: OutlineInputBorder(
                                              borderRadius:
                                                  BorderRadius.circular(10),
                                              borderSide: BorderSide.none),
                                          hintText: 'Write a comment'),
                                    ),
                                  ),
                                ),
                                if (isLoggedIn())
                                  GestureDetector(
                                      onTap: () async {
                                        if (!(await appIsOnline())) {
                                          return;
                                        }
                                        // Validate returns true if the form is valid, or false otherwise.
                                        if (_comment != '') {
                                          await _prayerRequestCubit
                                              .postPrayerRequestComment(
                                                  prayerId: widget
                                                      .prayer.prayerRequestId,
                                                  memberEmail:
                                                      getMemberEntityIfLoggedIn()
                                                          .memberEmail
                                                          .toString(),
                                                  text: _comment);
                                          _comment = '';
                                          // ignore: use_build_context_synchronously
                                          // Navigator.pop(context);
                                          // ignore: use_build_context_synchronously
                                          setState(() {});
                                          FocusManager.instance.primaryFocus
                                              ?.unfocus();
                                        }
                                      },
                                      child: const Icon(Icons.send))
                                else
                                  Builder(