Flutter图片水印插件 flutter_watermark 的使用

flutter_watermark 是一个帮助你在Flutter应用中全局添加水印的新插件。本文将介绍如何使用该插件，并提供完整的示例代码。

截图

使用方法

初始化插件

首先，你需要初始化插件：

final DisableScreenshots _plugin = DisableScreenshots();

添加默认样式的水印

你可以通过以下方式添加默认样式的水印：

_plugin.addWatermark(context, "默认水印", rowCount: 4, columnCount: 8);

添加自定义Widget作为水印

你也可以通过传递自定义的Widget来创建水印：

_plugin.addCustomWatermark(
    context,
    const Watermark(
        rowCount: 3, 
        columnCount: 10, 
        text: "自定义水印"
    )
);

移除水印

当需要移除水印时，调用以下方法：

_plugin.removeWatermark();

完整示例代码

以下是完整的示例代码，展示了如何在你的Flutter应用中集成和使用flutter_watermark插件：

import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter_watermark/flutter_watermark.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(home: RootApp());
  }
}

class RootApp extends StatelessWidget {
  RootApp({super.key});

  // 初始化插件
  final DisableScreenshots _plugin = DisableScreenshots();

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('全局水印'),
      ),
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            ElevatedButton(
                onPressed: () => _plugin.addWatermark(context, "默认水印",
                    rowCount: 4, columnCount: 8),
                child: const Text("添加默认水印")),
            ElevatedButton(
                onPressed: () => _plugin.addCustomWatermark(
                    context,
                    const Watermark(
                        rowCount: 3, columnCount: 10, text: "自定义水印")),
                child: const Text("添加自定义水印")),
            ElevatedButton(
                onPressed: () => _plugin.removeWatermark(),
                child: const Text("删除水印")),
            ElevatedButton(
                onPressed: () => Navigator.of(context).push(MaterialPageRoute(
                    builder: (_) => Scaffold(
                          appBar: AppBar(
                            title: const Text("我是新页面"),
                          ),
                          body: const Center(child: Text("new page")),
                        ))),
                child: const Text("进入新页面"))
          ],
        ),
      ),
    );
  }
}

class Watermark extends StatelessWidget {
  final int rowCount;
  final int columnCount;
  final String text;

  const Watermark({
    Key? key,
    required this.rowCount,
    required this.columnCount,
    required this.text,
  }) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return IgnorePointer(
      child: Column(
        children: createColumnWidgets(),
      ),
    );
  }

  List<Widget> createRowWidgets() {
    List<Widget> list = [];
    for (var i = 0; i < rowCount; i++) {
      final widget = Expanded(
          child: Center(
              child: Transform.rotate(
        angle: pi / 10,
        child: Text(
          text,
          style: const TextStyle(
              color: Color(0x08000000),
              fontSize: 18,
              decoration: TextDecoration.none),
        ),
      )));
      list.add(widget);
    }
    return list;
  }

  List<Widget> createColumnWidgets() {
    List<Widget> list = [];
    for (var i = 0; i < columnCount; i++) {
      final widget = Expanded(
          child: Row(
        children: createRowWidgets(),
      ));
      list.add(widget);
    }
    return list;
  }
}