Flutter 全局点击空白处隐藏键盘实战

class DismissKeyboardDemo extends StatelessWidget {
 final FocusNode focusNode = FocusNode();

 @override
 Widget build(BuildContext context) {
  return Scaffold(
   appBar: AppBar(),
   body: GestureDetector(
    onTap: () {
     focusNode.unfocus();
    },
    child: Container(
     color: Colors.transparent,
     alignment: Alignment.center,
     child: TextField(
      focusNode: focusNode,
     ),
    ),
   ),
  );
 }
}

class MyApp extends StatelessWidget {
 @override
 Widget build(BuildContext context) {
  return MaterialApp(
   title: 'Flutter Demo',
   builder: (context, child) => Scaffold(
    body: GestureDetector(
     onTap: () {
      FocusScopeNode currentFocus = FocusScope.of(context);
      if (!currentFocus.hasPrimaryFocus &&
        currentFocus.focusedChild != null) {
       FocusManager.instance.primaryFocus.unfocus();
      }
     },
     child: child,
    ),
   ),
   home: DismissKeyboardDemo(),
  );
 }
}

SystemChannels.textInput.invokeMethod('TextInput.hide');

class DismissKeyboardDemo extends StatelessWidget {

 @override
 Widget build(BuildContext context) {
  return Scaffold(
   appBar: AppBar(),
   body: Center(
    child: TextField(),
   ),
  );
 }
}