Flutter TextFormField，focusNode.requestFocus 工作一次然后键盘不显示

Question

目标：按下发送按钮时，不要关闭键盘并保持打开/聚焦 问题：按下发送按钮时，键盘关闭，然后由于focusNode.requestFocus重新打开，之后按下发送按钮时，键盘不再打开 寻找两个选项：

1. （理想）按下发送按钮时不要让键盘关闭
2. (okay) 无论发送按钮关闭多少次都打开键盘

   这是示例用户界面：

   return Form(
     key: _formKey,
     child: Row(
       children: <Widget>[
         Expanded(
           child: TextFormField(
             focusNode: chatController.focusNode,
             // textInputAction: TextInputAction.none, // didn't help
             // onEditingComplete: () {}, // didn't help
           )
         ),
   
         IconButton(
           icon: const Icon(Icons.send),
           onPressed: () async {
             SystemChannels.textInput
                 .invokeMethod('TextInput.hide');
             if (_formKey.currentState!.validate()) {
               await chatController.sendMessage(context);
             }
           }
         ),
       ],
     )
   );
   

   这是控制器：

   late FocusNode focusNode;
   
   @override
   void onReady() async { // tried onInit as well
     focusNode = FocusNode();
     super.onReady();
   }
   
   void sendMessage(BuildContext context) async {
     // focusNode.unfocus(); // didn't help
     // focusNode2.requestFocus(); // tried to give focus to another widget and take it back, but didn't help
     final a1 = focusNode.hasFocus; // except the very first call, this is true even when focusNode.unfocus() is called
   
     // neither of these work the second time
     focusNode.requestFocus();
     // FocusScope.of(context).requestFocus(focusNode);
   }
   

   我能够跟踪代码，并且当第二次呼叫到达焦点管理器here 时，此条件始终为真：

   if (hasPrimaryFocus && (_manager!._markedForFocus == null || _manager!._markedForFocus == this)) {
   

   即使键盘已关闭，它也会返回而不会再次尝试打开键盘

Answer 1

你有一个流浪者：

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

在您的 IconButton 回调中，它应该在删除后工作。