Flutter键盘可见性检测插件keyboard_visibility的使用

Flutter键盘可见性检测插件keyboard_visibility的使用

简介

keyboard_visibility 是一个用于监听软键盘可见性的 Flutter 插件。它可以在 Android 和 iOS 平台上提供键盘可见状态的变化通知。

使用步骤

1. 添加依赖

   在项目的 pubspec.yaml 文件中添加以下依赖：

   dependencies:
     keyboard_visibility: ^[CURRENT VERSION NUMBER]
   

   注意：确保在每一行的开头保留两个空格。

   添加完成后，运行以下命令以获取依赖：

   flutter packages get
   

2. 导入并初始化

   导入 keyboard_visibility 包，并在 initState 方法中注册键盘可见性监听器。

   import 'package:keyboard_visibility/keyboard_visibility.dart';
   
   [@protected](/user/protected)
   void initState() {
     super.initState();
   
     // 注册键盘可见性监听器
     KeyboardVisibilityNotification().addNewListener(
       onChange: (bool visible) {
         print(visible); // 打印键盘是否可见
       },
     );
   }
   

3. 完整示例代码

   下面是一个完整的示例代码，展示如何使用 keyboard_visibility 插件来检测键盘的可见性。

   import 'package:flutter/material.dart';
   import 'package:keyboard_visibility/keyboard_visibility.dart';
   
   void main() {
     runApp(MyApp());
   }
   
   class MyApp extends StatelessWidget {
     @override
     Widget build(BuildContext context) {
       return MaterialApp(
         title: '键盘可见性示例',
         theme: ThemeData(
           primarySwatch: Colors.blue,
         ),
         home: KeyboardVisibilityExample(),
       );
     }
   }
   
   class KeyboardVisibilityExample extends StatefulWidget {
     KeyboardVisibilityExample({Key key}) : super(key: key);
   
     @override
     _KeyboardVisibilityExampleState createState() => _KeyboardVisibilityExampleState();
   }
   
   class _KeyboardVisibilityExampleState extends State<KeyboardVisibilityExample> {
     KeyboardVisibilityNotification _keyboardVisibility = KeyboardVisibilityNotification();
     int _keyboardVisibilitySubscriberId;
     bool _keyboardState;
   
     [@protected](/user/protected)
     void initState() {
       super.initState();
   
       // 初始化键盘状态
       _keyboardState = _keyboardVisibility.isKeyboardVisible;
   
       // 注册键盘可见性监听器
       _keyboardVisibilitySubscriberId = _keyboardVisibility.addNewListener(
         onChange: (bool visible) {
           setState(() {
             _keyboardState = visible; // 更新键盘状态
           });
         },
       );
     }
   
     @override
     void dispose() {
       // 移除键盘可见性监听器
       _keyboardVisibility.removeListener(_keyboardVisibilitySubscriberId);
       super.dispose();
     }
   
     @override
     Widget build(BuildContext context) {
       return Scaffold(
         appBar: AppBar(
           title: Text('键盘可见性示例'),
         ),
         body: Center(
           child: Padding(
             padding: EdgeInsets.all(24.0),
             child: Column(
               mainAxisAlignment: MainAxisAlignment.center,
               children: <Widget>[
                 TextField(
                   keyboardType: TextInputType.text,
                   decoration: InputDecoration(
                     labelText: '输入框测试键盘',
                   ),
                 ),
                 SizedBox(height: 60.0), // 添加间距
                 Text(
                   '当前键盘状态: ${_keyboardState ? '可见' : '不可见'}',
                   style: TextStyle(fontSize: 18.0),
                 ),
               ],
             ),
           ),
         ),
       );
     }
   }