如何增加onLongPress的时间限制？

import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';

class LongPressWidget extends StatefulWidget {
  @override
  _LongPressWidgetState createState() => _LongPressWidgetState();
}

class _LongPressWidgetState extends State<LongPressWidget> {
  bool _isLongPressing = false;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onLongPress: _startLongPress,
      onLongPressMoveUpdate: _handleLongPressMoveUpdate,
      onLongPressEnd: _endLongPress,
      child: Container(
        width: 200,
        height: 200,
        color: _isLongPressing ? Colors.red : Colors.blue,
      ),
    );
  }

  void _startLongPress() {
    setState(() {
      _isLongPressing = true;
    });

    // 设置长按持续时间为3秒
    Timer(Duration(seconds: 3), () {
      if (_isLongPressing) {
        // 长按时间达到3秒后执行相应操作
        print('Long press action');
      }
    });
  }

  void _handleLongPressMoveUpdate(LongPressMoveUpdateDetails details) {
    // 处理长按移动事件
  }

  void _endLongPress() {
    setState(() {
      _isLongPressing = false;
    });
  }
}

import 'package:flutter/material.dart';

class LongPressWidget extends StatefulWidget {
  @override
  _LongPressWidgetState createState() => _LongPressWidgetState();
}

class _LongPressWidgetState extends State<LongPressWidget> {
  bool _isLongPressing = false;
  Timer _timer;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onLongPress: _startLongPress,
      onLongPressEnd: _endLongPress,
      child: Container(
        width: 200,
        height: 200,
        color: _isLongPressing ? Colors.red : Colors.blue,
      ),
    );
  }

  void _startLongPress() {
    setState(() {
      _isLongPressing = true;
    });

    // 设置长按持续时间为3秒
    _timer = Timer(Duration(seconds: 3), () {
      if (_isLongPressing) {
        // 长按时间达到3秒后执行相应操作
        print('Long press action');
      }
    });
  }

  void _endLongPress() {
    setState(() {
      _isLongPressing = false;
    });

    // 取消定时器
    _timer?.cancel();
  }
}