颤振：如何在每个图像上放置按钮，如（x）来取消所选图像

Question

我在我的应用程序中使用multi_image_picker 4.6.1，但是我遇到的问题很少。如何在页面上的特定位置组织图像并将取消按钮放在每个选定的图像上，以便用户可以像在图片here中一样逐个取消或除去选定的图像。在此先感谢

这是我使用的代码

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

import 'package:multi_image_picker/multi_image_picker.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  List<Asset> images = List<Asset>();
  String _error = 'No Error Dectected';

  @override
  void initState() {
    super.initState();
  }

  Widget buildGridView() {
    return GridView.count(
      crossAxisCount: 3,
      children: List.generate(images.length, (index) {
        Asset asset = images[index];
        return AssetThumb(
          asset: asset,
          width: 300,
          height: 300,
        );
      }),
    );
  }

  Future<void> loadAssets() async {
    List<Asset> resultList = List<Asset>();
    String error = 'No Error Dectected';

    try {
      resultList = await MultiImagePicker.pickImages(
        maxImages: 300,
        enableCamera: true,
        selectedAssets: images,
        cupertinoOptions: CupertinoOptions(takePhotoIcon: "chat"),
        materialOptions: MaterialOptions(
          actionBarColor: "#abcdef",
          actionBarTitle: "Example App",
          allViewTitle: "All Photos",
          useDetailsView: false,
          selectCircleStrokeColor: "#000000",
        ),
      );
    } on Exception catch (e) {
      error = e.toString();
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      images = resultList;
      _error = error;
    });
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: const Text('Plugin example app'),
        ),
        body: Column(
          children: <Widget>[
            Center(child: Text('Error: $_error')),
            RaisedButton(
              child: Text("Pick images"),
              onPressed: loadAssets,
            ),
            Expanded(
              child: buildGridView(),
            )
          ],
        ),
      ),
    );
  }
}

Answer 1

您可以尝试使用Stack https://www.youtube.com/watch?v=liEGSeD3Zt8&vl=en

return Stack(
  children: <Widget>[
    AssetThumb(
      asset: asset,
      width: 300,
      height: 300,
    ),
    Positioned(
      top: 0,
      right: 0,
      child: GestureDetector(
          onTap: () => print('delete image from List')
          child: Icon(
        Icons.delete,
      ),
     ),
    ),
  ],
);