点击空白处收起键盘

法1： FocusScope.of(context).requestFocus(FocusNode());
法2: FocusManager.instance.primaryFocus?.unfocus();
以上这两个方法可点击空白处(除了状态栏处)收起键盘，并且输入框失去焦点

SystemChannels.textInput.invokeMethod('TextInput.hide'); //收起键盘，但输入框焦点不会失去
SystemChannels.textInput.invokeMethod('TextInput.show'); //弹出键盘，但不会有输入框焦点(输入框光标不显示)

FocusNode textFocus1 = FocusNode();
textFocus1.requestFocus(); //输入框聚焦，并且弹出键盘

自动弹出键盘，可以设置TextField的autofocus属性为true
autofocus: true, //是否自动设置焦点，也就是自动打开手机键盘，定位到此控件以便输入内容；Windows端则是光标自动定位。

import 'package:flutter/cupertino.dart';
import 'package:get/get.dart';

class TextFieldController extends GetxController {

  TextEditingController textController1 = TextEditingController();
  FocusNode textFocus1 = FocusNode();
  TextEditingController textController2 = TextEditingController();
  FocusNode textFocus2 = FocusNode();


  @override
  void onReady() {
    super.onReady();

    Future.delayed(const Duration(seconds: 1), (){
      SystemChannels.textInput.invokeMethod('TextInput.show');
    });
  }

//输入框失去焦点（失去焦点会触发收起键盘）
unFocus() {
    if(textFocus1.hasFocus){
      textFocus1.unfocus();
    }
    if(textFocus2.hasFocus){
      textFocus2.unfocus();
    }
  }
}



import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:get/get.dart';

import 'controller/text_field_controller.dart';
class TextFieldPage extends GetView<TextFieldController> {
  const TextFieldPage({Key? key}) : super(key: key);

 
  @override
  Widget build(BuildContext context) {
    Get.put(TextFieldController());

    return GestureDetector(
      behavior: HitTestBehavior.opaque,      //要设置behavior属性，不然可能点击无效
      onTap: (){
       FocusScope.of(context).requestFocus(FocusNode());
      //FocusManager.instance.primaryFocus.unfocus();
      },
      child: Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(title: const Text('TextField')),
      body: Container(
        margin: EdgeInsets.symmetric(horizontal: 10.w),
        child: Column(children: [
          TextField(
        controller: controller.textController1,
        focusNode: controller.textFocus1,
      ),
      SizedBox(height: 25.w,),
      TextField(
        controller: controller.textController2,
        focusNode: controller.textFocus2,
      ),
        ],)
      ),
    ),
    );
  
  }

}

flutter_keyboard_visibility插件 点击空白处(除了状态栏处)隐藏键盘、失去焦点

导入插件

 #点击空白处隐藏键盘
  flutter_keyboard_visibility: ^5.3.0

点击空白处隐藏键盘
(new) KeyboardDismissOnTap KeyboardDismissOnTap({
Key? key,
required Widget child,
bool dismissOnCapturedTaps = false,
})

获取键盘是否隐藏回调，局部刷新组件
(new) KeyboardVisibilityBuilder KeyboardVisibilityBuilder({
Key? key,
required Widget Function(BuildContext, bool) builder,
KeyboardVisibilityController? controller,
})

import 'package:flutter_keyboard_visibility/flutter_keyboard_visibility.dart';

 return KeyboardDismissOnTap(       //点击空白处隐藏键盘
      child: Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(title: const Text('TextField')),
      body: Container(
        margin: EdgeInsets.symmetric(horizontal: 10.w),
        child: Column(children: [
          Container(
            color: Colors.amber[200],
            child: KeyboardVisibilityBuilder(builder: (context, visible){     //获取键盘是否隐藏回调，局部刷新组件
              return Text('The keyboard is ${visible ? 'VISIBLE' : 'NOT VISIBLE'}');
            },),
          ),
          TextField(
        controller: controller.textController1,
        focusNode: controller.textFocus1,
      ),
        SizedBox(height: 25.w,),
        TextField(
          controller: controller.textController2,
          focusNode: controller.textFocus2,
        ),
        
          const Spacer(),
          ]
        ),
      )
    )
      );

弹出键盘时，渲染越界的处理

1.如果使用的是Scaffold 组件，可以设置
resizeToAvoidBottomInset:false
2.也可以 使用SingleChildScrollView来进行包裹下
new SingleChildScrollView(
child: 你的组件
)