flutter实现扫码枪获取数据源禁止系统键盘弹窗示例详解

dependencies:
  scan_gun: ^1.0.0

  ScanMonitorWidget({
    Key? key,
    required ChildBuilder childBuilder,
    FocusNode? scanNode,
    FocusNode? textFiledNode,
    required void Function(String) onSubmit,
  })

@override
  Widget build(BuildContext context) {
    return ScanMonitorWidget(
      childBuilder: (context) {
        return body();
      },
      onSubmit: (String result) {
        print(result); //接收到扫码结果
      },
    );
  }

FocusNode textFiledNode = FocusNode();
TextEditingController controller = TextEditingController();
 Widget body() {
  return TextField(
     focusNode: textFiledNode,
     controller: controller,
   );
 }
@override
  Widget build(BuildContext context) {
    return ScanMonitorWidget(
      textFiledNode: textFiledNode,
      childBuilder: (context) {
        return body();
      },
      onSubmit: (String result) {
        print(result); //接收到扫码结果
      },
    );
  }

    return Stack(
      children: [
        //让输入框保持隐藏
        Offstage(child: edtWidget, offstage: true),
        child,
      ],
    );

  void listenKeyboard() {
    SystemChannels.textInput.setMethodCallHandler((call) => _handleTextInputInvocation(call));
  }

String scanData = '';
void _update(){
    setState(() {});
  }
Future<dynamic> _handleTextInputInvocation(MethodCall methodCall) async {
    final String method = methodCall.method;
    final List<dynamic> args = methodCall.arguments as List<dynamic>;
    switch (method) {
      case 'TextInputClient.updateEditingState': //每次的内容变化会进来这里
        final data = TextEditingValue.fromJSON(args[1] as Map<String, dynamic>);
        final text = data.text;
        scanData += text;
        dev.log('rex: -updateEditingState - $text');
        break;
      case 'TextInputClient.performAction':
        final action = args[1] as String;
        dev.log('rex: -performAction - $action');
        if(action == 'TextInputAction.none'){ //点击确定
          _update();
        }
        break;
      default:
        throw MissingPluginException();
    }
  }