Flutter安全保存图片插件gallery_saver_safety的使用

说明

本插件是 gallery_saver 插件的一个副本，已迁移到 Null Safety。

使用说明

gallery_saver_safety 插件用于将网络或临时文件中的图片和视频保存到外部存储。保存后的图片和视频将在Android Gallery和iOS Photos中可见。

注意：如果你想要保存网络图片或视频链接，则该链接必须包含 http 或 https 前缀。

安装

首先，在你的 pubspec.yaml 文件中添加 gallery_saver_safety 作为依赖项。

iOS

在 Info.plist 文件中添加以下键：

<key>NSPhotoLibraryUsageDescription</key>
<string>描述为什么应用需要访问照片库的权限。</string>

Android

在 AndroidManifest.xml 文件中添加以下权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

示例代码

以下是完整的示例代码，展示了如何使用 gallery_saver_safety 插件来保存图片和视频。

import 'dart:io';
import 'dart:typed_data';
import 'dart:ui' as ui;

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:gallery_saver_safety/gallery_saver_safety.dart';
import 'package:image_picker/image_picker.dart';
import 'package:path_provider/path_provider.dart';

double textSize = 20;

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

class MyApp extends StatefulWidget {
  [@override](/user/override)
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String firstButtonText = '拍摄照片';
  String secondButtonText = '录制视频';
  String screenshotButtonText = '保存截图';

  String albumName = '媒体';

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
        home: Scaffold(
      body: SafeArea(
        child: Container(
          color: Colors.white,
          child: Column(
            children: <Widget>[
              Flexible(
                flex: 1,
                child: Container(
                  child: SizedBox.expand(
                    child: RaisedButton(
                      color: Colors.blue,
                      onPressed: _takePhoto,
                      child: Text(firstButtonText,
                          style: TextStyle(
                              fontSize: textSize, color: Colors.white)),
                    ),
                  ),
                ),
              ),
              ScreenshotWidget(),
              Flexible(
                child: Container(
                    child: SizedBox.expand(
                  child: RaisedButton(
                    color: Colors.white,
                    onPressed: _recordVideo,
                    child: Text(secondButtonText,
                        style: TextStyle(
                            fontSize: textSize, color: Colors.blueGrey)),
                  ),
                )),
                flex: 1,
              )
            ],
          ),
        ),
      ),
    ));
  }

  void _takePhoto() async {
    ImagePicker.platform.pickImage(source: ImageSource.camera)
        .then((PickedFile recordedImage) {
      if (recordedImage != null && recordedImage.path != null) {
        setState(() {
          firstButtonText = '保存中...';
        });
        GallerySaver.saveImage(recordedImage.path, albumName: albumName)
            .then((bool success) {
          setState(() {
            firstButtonText = '照片已保存！';
          });
        });
      }
    });
  }

  void _recordVideo() async {
    ImagePicker.platform.pickVideo(source: ImageSource.camera)
        .then((PickedFile recordedVideo) {
      if (recordedImage != null && recordedImage.path != null) {
        setState(() {
          secondButtonText = '保存中...';
        });
        GallerySaver.saveVideo(recordedVideo.path, albumName: albumName)
            .then((bool success) {
          setState(() {
            secondButtonText = '视频已保存！';
          });
        });
      }
    });
  }

  void _saveNetworkVideo() async {
    String path = 'https://sample-videos.com/video123/mp4/720/big_buck_bunny_720p_1mb.mp4';
    GallerySaver.saveVideo(path, albumName: albumName).then((bool success) {
      setState(() {
        print('视频已保存');
      });
    });
  }

  void _saveNetworkImage() async {
    String path = 'https://image.shutterstock.com/image-photo/montreal-canada-july-11-2019-600w-1450023539.jpg';
    GallerySaver.saveImage(path, albumName: albumName).then((bool success) {
      setState(() {
        print('图片已保存');
      });
    });
  }
}

class ScreenshotWidget extends StatefulWidget {
  [@override](/user/override)
  _ScreenshotWidgetState createState() => _ScreenshotWidgetState();
}

class _ScreenshotWidgetState extends State<ScreenshotWidget> {
  final GlobalKey _globalKey = GlobalKey();

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Flexible(
      flex: 1,
      child: RepaintBoundary(
        key: _globalKey,
        child: Container(
          child: SizedBox.expand(
            child: RaisedButton(
              color: Colors.pink,
              onPressed: _saveScreenshot,
              child: Text(screenshotButtonText,
                  style: TextStyle(fontSize: textSize, color: Colors.white)),
            ),
          ),
        ),
      ),
    );
  }

  Future<void> _saveScreenshot() async {
    setState(() {
      screenshotButtonText = '保存中...';
    });
    try {
      // 提取字节
      final RenderRepaintBoundary boundary = _globalKey.currentContext.findRenderObject();
      final ui.Image image = await boundary.toImage(pixelRatio: 3.0);
      final ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
      final Uint8List pngBytes = byteData.buffer.asUint8List();

      // 创建文件
      final String dir = (await getApplicationDocumentsDirectory()).path;
      final String fullPath = '$dir/${DateTime.now().millisecond}.png';
      File capturedFile = File(fullPath);
      await capturedFile.writeAsBytes(pngBytes);
      print(capturedFile.path);

      await GallerySaver.saveImage(capturedFile.path)
          .then((value) {
            setState(() {
              screenshotButtonText = '截图已保存！';
            });
      });
    } catch (e) {
      print(e);
    }
  }
}