如何在颤振中创建三次单击按钮

Question

How can I implement a triple-click button in flutter?

On triple-click, the button will store an entry in Firebase database.

Answer 1

Its pretty easy. You can use a GestureDetector() to check for the number of taps then you can provide your logic if there are 3 taps.

GestureDetector(
        onTap: () {
          int now = DateTime.now().millisecondsSinceEpoch;
          if (now - lastTap < 1000) {
            print("Consecutive tap");
            consecutiveTaps ++;
            print("taps = " + consecutiveTaps.toString());
            if (consecutiveTaps == 3){
              // Do something
            }
          } else {
            consecutiveTaps = 0;
          }
          lastTap = now;
        },
        child: ...
)

Answer 2

Implementing "triple click" button in flutter might not be possible. But, if you really want to make it work ASAP then a simple method could be to maintain a counter for the number of clicks done. Once the count reaches 3, you need to add your entry to Firestore.

I have modified the code from the counter app boilerplate of flutter.
Hope you have cloud_firestore in your pubspec.yaml file. If not then add it and put the services.json as well in the app folder of android or respective directory of ios.

cloud_firestore: ^0.13.4+1

So, now you can have a look at the code that I am using.

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  _incrementCounter() {
    setState(() {
      _counter++;
    });
    if (_counter == 3) {
      Firestore.instance
          .collection('/sampleData')
          .add({'data': "data"}).catchError((e) {
        print(e);
      });
      setState(() {
        _counter = 0;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

I have edited the _incrementCounter function. I added a conditional statement to check the _counter if it is 3 or not. Then, I am adding the Firestore entry. Later on, the most important bit is to set the _counter as 0 so that the next time the user presses the button 3 times, then the code will work accordingly. You can customize it according to your needs.

But remember, triple clicks have not been yet invented in flutter and this is just a work-around solution and don't use it for Real-life Development applications as this would be a very bad practice.