import 'package:flutter/material.dart';

void main2() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: DragIconDemo());
  }
}

class DragIconDemo extends StatefulWidget {
  @override
  _DragIconDemoState createState() => _DragIconDemoState();
}

class _DragIconDemoState extends State<DragIconDemo> {
  // 跟踪图标在哪个容器中（1或2）
  int iconContainer = 1;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('图标拖拽示例')),
      body: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: [
          // 第一个容器
          buildContainer(
            containerNumber: 1,
            child: iconContainer == 1 ? buildDraggableIcon() : null,
          ),

          // 第二个容器
          buildContainer(
            containerNumber: 2,
            child: iconContainer == 2 ? buildDraggableIcon() : null,
          ),
        ],
      ),
    );
  }

  // 构建可拖拽图标
  Widget buildDraggableIcon() {
    return Draggable<int>(
      data: iconContainer, // 传递当前容器编号作为数据
      feedback: const Icon(Icons.star, size: 50, color: Colors.amber),
      childWhenDragging: const Opacity(
        opacity: 0.5,
        child: Icon(Icons.star, size: 50, color: Colors.amber),
      ),
      child: const Icon(Icons.star, size: 50, color: Colors.amber),
    );
  }

  // 构建容器（同时也是拖放目标）
  Widget buildContainer({required int containerNumber, Widget? child}) {
    return DragTarget<int>(
      builder: (context, candidateData, rejectedData) {
        return Container(
          width: 150,
          height: 150,
          decoration: BoxDecoration(
            border: Border.all(color: Colors.blue, width: 2),
            borderRadius: BorderRadius.circular(10),
          ),
          child: Center(child: child),
        );
      },
      onWillAcceptWithDetails: (data) => true, // 接受任何拖拽数据
      onAcceptWithDetails: (data) {
        setState(() {
          iconContainer = containerNumber; // 更新图标位置
        });
      },
    );
  }
}