Flutter开发-自定义组件

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

class ToastHelper {
  static void showToast(BuildContext context, String text) {
    const style = TextStyle(color: Colors.white, fontSize: 16.0);

    Widget widget = Center(
      child: Material(
        child: Container(
          padding: const EdgeInsets.symmetric(vertical: 10.0, horizontal: 10.0),
          decoration: BoxDecoration(
              color: Colors.black.withOpacity(0.5),
              borderRadius: BorderRadius.all(Radius.circular(6))),
          child: Text(
            text,
            textAlign: TextAlign.center,
            style: style,
          ),
        ),
      ),
    );
    var entry = OverlayEntry(
      builder: (_) => widget,
    );

    Overlay.of(context).insert(entry);

    Timer(const Duration(seconds: 2), () {
      entry?.remove();
    });
  }
}

ToastHelper.showToast(context, "双击两次退出！");