使用FLutter开发了一个图片选择的组件，功能如下：

1、支持设置最大可选图片的个数；

2、根据选择的图片个数自适应容器组件的高度；

3、可设置容器的最大高度；

4、支持点击放大和删除功能；

具体效果如下

使用到的三方插件：

get: ^4.6.6 #路由管理
flutter_easyloading: ^3.0.5 #加载动画、弹框
image_picker: ^1.0.4 #图片选择器
photo_view: ^0.14.0 #点击图片处理–放大，缩放、滑动

代码如下：

1、先添加相册、相机权限

iOS

	<key>NSCameraUsageDescription</key>
	<string>更换个人头像需要使用相机功能</string>
	<key>NSPhotoLibraryAddUsageDescription</key>
	<string>更换个人头像需要使用相册功能</string>
	<key>NSPhotoLibraryUsageDescription</key>
	<string>更换个人头像需要使用相册功能</string>

Android

    <!-- 摄像头 -->
    <uses-permission android:name="android.permission.CAMERA" />
    <!-- 文件读取 -->
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="32"/>
    <!--    Android 13 READ_EXTERNAL_STORAGE权限需要使用READ_MEDIA_IMAGE、READ_MEDIA_VIDEO、READ_MEDIA_AUDIO 来替代适配 -->
    <uses-permission android:name="android.permission.READ_MEDIA_IMAGE" />
    <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />

2、创建一个ImagePickerMul的类

import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_easyloading/flutter_easyloading.dart';
import 'package:get/get.dart';
import 'package:image_picker/image_picker.dart';
import 'package:photo_view/photo_view.dart';

class ImagePickerMul extends StatefulWidget {
  final int maxCount; //最大选择图片数量
  final double maxHeight; //图片容器的最大高度
  final Function(List<XFile>) pickerImgCallBack; //选取图片成功之后拿到返回结果
  const ImagePickerMul({
    super.key,
    this.maxCount = 1000,
    this.maxHeight = 300.0,
    required this.pickerImgCallBack,
  });

  @override
  State<ImagePickerMul> createState() => _ImagePickerMulState();
}

class _ImagePickerMulState extends State<ImagePickerMul> {
  final List<XFile> _imageFileList = []; //存放图片的数组
  final ImagePicker _picker = ImagePicker();
  dynamic _pickerImageError;
  int _bigImageIndex = 0; //存放需要放大的图片下标

  // 获取当前展示图的数量
  int getImageCount() {
    widget.pickerImgCallBack(_imageFileList);
    if (_imageFileList.length < widget.maxCount) {
      return _imageFileList.length + 1;
    } else {
      return _imageFileList.length;
    }
  }

  void _onImageButtonPressed(
    ImageSource source, {
    double? maxHeight,
    double? maxWidth,
    int? imageQuality,
  }) async {
    try {
      final pickedFileList = await _picker.pickMultipleMedia(
        maxHeight: maxHeight,
        maxWidth: maxWidth,
        imageQuality: imageQuality,
      );
      setState(() {
        if (_imageFileList.length < widget.maxCount) {
          if ((_imageFileList.length + pickedFileList.length) <=
              widget.maxCount) {
            //加上新选的不能超过总数量
            for (var element in pickedFileList) {
              _imageFileList.add(element);
            }
          } else {
            EasyLoading.showToast(
              '最多只能选取${widget.maxCount}张图片，多余的图片将会自动删除！',
              duration: const Duration(milliseconds: 1500),
            );
            int avaliableCount = widget.maxCount - _imageFileList.length;
            for (int i = 0; i < avaliableCount; i++) {
              _imageFileList.add(pickedFileList[i]);
            }
          }
        }
      });
    } catch (e) {
      EasyLoading.showToast('$_pickerImageError');
      _pickerImageError = e;
    }
  }

  void _removeImage(int index) {
    setState(() {
      _imageFileList.removeAt(index);
    });
  }

  void _showBigImage(int index) {
    setState(() {
      _bigImageIndex = index;
    });
    //点击图片放大
    showDialog(
      context: context,
      builder: (context) {
        return Dialog(
          insetPadding: const EdgeInsets.only(left: 0.0),
          child: PhotoView(
            tightMode: true,
            imageProvider: FileImage(
              File(
                _imageFileList[_bigImageIndex].path,
              ),
            ),
          ),
        );
      },
    );
  }

  Widget? displayBigImage() {
    if (_imageFileList.length > _bigImageIndex) {
      return Image.file(
        File(
          _imageFileList[_bigImageIndex].path,
        ),
        fit: BoxFit.cover,
      );
    } else {
      return null;
    }
  }

  @override
  Widget build(BuildContext context) {
    int columnCount = 0;
    if (_imageFileList.length == widget.maxCount) {
      columnCount = (widget.maxCount / 3).ceil();
    } else {
      columnCount = ((_imageFileList.length + 1) / 3).ceil();
    }
    return _imageFileList.isNotEmpty
        ? Container(
            height: columnCount * (Get.width / 3),
            constraints: BoxConstraints(
              maxHeight: widget.maxHeight,
            ),
            child: GridView.builder(
              gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 3,
                childAspectRatio: 1.0,
              ),
              itemBuilder: (context, index) {
                if (_imageFileList.length < widget.maxCount) {
                  if (index < _imageFileList.length) {
                    return Padding(
                      padding: const EdgeInsets.all(10.0),
                      child: Stack(
                        alignment: Alignment.center,
                        children: [
                          Positioned(
                            top: 0.0,
                            left: 0.0,
                            bottom: 0.0,
                            right: 0.0,
                            child: GestureDetector(
                              child: Image.file(
                                File(
                                  _imageFileList[index].path,
                                ),
                                fit: BoxFit.cover,
                              ),
                              onTap: () => _showBigImage(index),
                            ),
                          ),
                          Positioned(
                            top: 0.0,
                            right: 0.0,
                            width: 20,
                            height: 20,
                            child: GestureDetector(
                              child: const Icon(
                                Icons.close,
                                color: Colors.white,
                              ),
                              onTap: () => _removeImage(index),
                            ),
                          ),
                        ],
                      ),
                    );
                  } else {
                    //显示添加符号
                    return Padding(
                      padding: const EdgeInsets.all(10.0),
                      child: IconButton(
                        onPressed: () => _onImageButtonPressed(
                          ImageSource.gallery,
                          imageQuality: 40, //图片压缩
                        ),
                        icon: const Icon(Icons.add_a_photo_outlined),
                      ),
                    );
                  }
                } else {
                  //选满了
                  return Container(
                    padding: const EdgeInsets.all(10.0),
                    child: Stack(
                      alignment: Alignment.center,
                      children: [
                        Positioned(
                          top: 0.0,
                          left: 0.0,
                          bottom: 0.0,
                          right: 0.0,
                          child: GestureDetector(
                            child: Image.file(
                              File(
                                _imageFileList[index].path,
                              ),
                              fit: BoxFit.cover,
                            ),
                            onTap: () => _showBigImage(index),
                          ),
                        ),
                        Positioned(
                          top: 0.0,
                          right: 0.0,
                          width: 20,
                          height: 20,
                          child: GestureDetector(
                            child: const SizedBox(
                              child: Icon(
                                Icons.close,
                                color: Colors.white,
                              ),
                            ),
                            onTap: () => _removeImage(index),
                          ),
                        ),
                      ],
                    ),
                  );
                }
              },
              itemCount: getImageCount(),
            ),
          )
        : SizedBox(
            width: 90,
            height: 90,
            child: IconButton(
              onPressed: () => _onImageButtonPressed(
                ImageSource.gallery,
                imageQuality: 40, //图片压缩
              ),
              icon: const Icon(Icons.add_a_photo_outlined),
            ),
          );
  }
}

3、使用

body: Container(
        color: Colors.yellow,
        child: ImagePickerMul(
          maxCount: 9,
          maxHeight: 300.0,
          pickerImgCallBack: (imageList) {},
        ),
      ),

本人将会持续更新在开发过程中遇到的各种小demo，如果喜欢的话，欢迎给个star，ღ( ´･ᴗ･` )比心