Flutter自由截图插件screenshot_freehand的使用

Flutter自由截图插件screenshot_freehand的使用

Screenshot_freehand 是一个用于 Flutter 应用程序的自由截图插件。它可以在所有平台上运行，并允许用户自由绘制矩形区域进行截图。

安装

首先，在你的 pubspec.yaml 文件中添加 screenshot_freehand 作为依赖项：

dependencies:
  screenshot_freehand: ^版本号

然后运行 flutter pub get 来安装该插件。

示例

以下是一个完整的示例代码，展示了如何在 Flutter 应用程序中使用 screenshot_freehand 插件。

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

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

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

class _ScreenShotState extends State<ScreenShot> {
  int _counter = 0;
  Uint8List? imageData;
  late final ScreenShotController screenShotController;

  [@override](/user/override)
  void initState() {
    super.initState();
    screenShotController = ScreenShotController();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Video Demo',
      home: ScreenShot(
        screenShotController: screenShotController,
        child: Scaffold(
          backgroundColor: Colors.amber.shade200,
          appBar: AppBar(
            backgroundColor: Theme.of(context).colorScheme.inversePrimary,
            title: Text(widget.title),
          ),
          body: Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                const Text(
                  '你已经点击了按钮这么多次:',
                ),
                Text(
                  '$_counter',
                  style: Theme.of(context).textTheme.headlineMedium,
                ),
                ElevatedButton(
                  onPressed: () async {
                    imageData = await screenShotController.takeSnapShot();
                    setState(() {});
                  },
                  child: const Text("截图"),
                ),
                if (imageData != null)
                  Container(
                    width: 400,
                    height: 350,
                    margin: const EdgeInsets.all(10),
                    decoration: BoxDecoration(
                      color: Colors.white,
                      border: Border.all(
                        color: Colors.green,
                      ),
                      image: DecorationImage(
                        image: MemoryImage(imageData!),
                      ),
                    ),
                  ),
              ],
            ),
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: () {
              setState(() {
                _counter++;
              });
            },
            tooltip: '增加',
            child: const Icon(Icons.add),
          ),
        ),
      ),
    );
  }
}

代码解释

  • 导入包：

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

  • 定义主应用：

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

  • 创建状态类：

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

  • 初始化状态类：

    class _ScreenShotState extends State<ScreenShot> {
  int _counter = 0;
  Uint8List? imageData;
  late final ScreenShotController screenShotController;

  [@override](/user/override)
  void initState() {
    super.initState();
    screenShotController = ScreenShotController();
  }

  • 构建UI：

    [@override](/user/override)
Widget build(BuildContext context) {
  return MaterialApp(
    title: 'Video Demo',
    home: ScreenShot(
      screenShotController: screenShotController,
      child: Scaffold(
        backgroundColor: Colors.amber.shade200,
        appBar: AppBar(
          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
          title: Text(widget.title),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              const Text(
                '你已经点击了按钮这么多次:',
              ),
              Text(
                '$_counter',
                style: Theme.of(context).textTheme.headlineMedium,
              ),
              ElevatedButton(
                onPressed: () async {
                  imageData = await screenShotController.takeSnapShot();
                  setState(() {});
                },
                child: const Text("截图"),
              ),
              if (imageData != null)
                Container(
                  width: 400,
                  height: 350,
                  margin: const EdgeInsets.all(10),
                  decoration: BoxDecoration(
                    color: Colors.white,
                    border: Border.all(
                      color: Colors.green,
                    ),
                    image: DecorationImage(
                      image: MemoryImage(imageData!),
                    ),
                  ),
                ),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            setState(() {
              _counter++;
            });
          },
          tooltip: '增加',
          child: const Icon(Icons.add),
        ),
      ),
    ),
  );
}

更多关于Flutter自由截图插件screenshot_freehand的使用的实战教程也可以访问 https://www.itying.com/category-92-b0.html

1 回复

更多关于Flutter自由截图插件screenshot_freehand的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html


flutter_screenshot_freehand 是一个用于在 Flutter 应用中实现自由截图功能的插件。它允许用户在屏幕上绘制一个自由形状的区域，并截取该区域的内容。以下是如何使用 flutter_screenshot_freehand 插件的基本步骤：

1. 添加依赖

首先，在 pubspec.yaml 文件中添加 flutter_screenshot_freehand 插件的依赖：

dependencies:
  flutter:
    sdk: flutter
  flutter_screenshot_freehand: ^0.1.0  # 请检查最新版本

然后运行 flutter pub get 来获取依赖。

2. 导入插件

在你的 Dart 文件中导入插件：

import 'package:flutter_screenshot_freehand/flutter_screenshot_freehand.dart';

3. 使用 ScreenshotFreehand 组件

你可以使用 ScreenshotFreehand 组件来实现自由截图功能。以下是一个简单的示例：

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

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

class _ScreenshotDemoState extends State<ScreenshotDemo> {
  GlobalKey _globalKey = GlobalKey();
  Image? _capturedImage;

  Future<void> _captureScreenshot() async {
    RenderRepaintBoundary boundary =
        _globalKey.currentContext!.findRenderObject() as RenderRepaintBoundary;
    var image = await boundary.toImage();
    ByteData? byteData = await image.toByteData(format: ImageByteFormat.png);
    Uint8List pngBytes = byteData!.buffer.asUint8List();

    setState(() {
      _capturedImage = Image.memory(pngBytes);
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Freehand Screenshot Demo'),
      ),
      body: Column(
        children: [
          Expanded(
            child: RepaintBoundary(
              key: _globalKey,
              child: ScreenshotFreehand(
                child: Center(
                  child: Text('Draw a freehand shape to capture'),
                ),
              ),
            ),
          ),
          if (_capturedImage != null)
            Expanded(
              child: Center(
                child: _capturedImage,
              ),
            ),
          ElevatedButton(
            onPressed: _captureScreenshot,
            child: Text('Capture Screenshot'),
          ),
        ],
      ),
    );
  }
}
回到顶部