chrome小插件：长图片等分切割

前置条件：

安装有chrome谷歌浏览器的电脑

使用步骤：

1.打开chrome扩展插件

2.点击管理扩展程序

3.加载已解压的扩展程序

4.选择对应文件夹

5.成功后会出现一个扩展小程序

6.点击对应小程序

7.选择图片进行切割，切割完成后会自动保存

代码：

1.manifest.json

java 复制代码

{
  "manifest_version": 3,
  "name": "图片裁切工具",
  "version": "1.0",
  "description": "将长图平均裁切成多份",
  "icons": {
    "128": "images/icon128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "images/icon128.png"
    }
  },
  "permissions": [
    "downloads"
  ]
}

2.popup.js

javascript 复制代码

document.addEventListener('DOMContentLoaded', function() {
  const imageInput = document.getElementById('imageInput');
  const preview = document.getElementById('preview');
  const partsInput = document.getElementById('parts');
  const splitButton = document.getElementById('splitButton');
  
  let selectedImage = null;

  imageInput.addEventListener('change', function(e) {
    const file = e.target.files[0];
    if (file) {
      const reader = new FileReader();
      reader.onload = function(e) {
        preview.src = e.target.result;
        preview.style.display = 'block';
        selectedImage = e.target.result;
      };
      reader.readAsDataURL(file);
    }
  });

  splitButton.addEventListener('click', function() {
    if (!selectedImage) {
      alert('请先选择图片！');
      return;
    }

    const parts = parseInt(partsInput.value);
    if (parts < 2) {
      alert('裁切份数必须大于等于2！');
      return;
    }

    const img = new Image();
    img.onload = function() {
      const canvas = document.createElement('canvas');
      const ctx = canvas.getContext('2d');
      
      const partHeight = Math.floor(img.height / parts);
      canvas.width = img.width;
      canvas.height = partHeight;

      for (let i = 0; i < parts; i++) {
        ctx.clearRect(0, 0, canvas.width, canvas.height);
        ctx.drawImage(
          img,
          0, i * partHeight, // 源图片裁切起始位置
          img.width, partHeight, // 源图片裁切尺寸
          0, 0, // canvas绘制起始位置
          canvas.width, canvas.height // canvas绘制尺寸
        );

        // 将canvas转换为blob并下载
        canvas.toBlob(function(blob) {
          const url = URL.createObjectURL(blob);
          chrome.downloads.download({
            url: url,
            filename: `split_${i + 1}.png`,
            saveAs: false
          });
        }, 'image/png');
      }
    };
    img.src = selectedImage;
  });
});

3.popup.html

html 复制代码

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <style>
    body {
      width: 300px;
      padding: 10px;
    }
    .container {
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    #preview {
      max-width: 100%;
      max-height: 200px;
      display: none;
    }
  </style>
</head>
<body>
  <div class="container">
    <input type="file" id="imageInput" accept="image/*">
    <img id="preview">
    <div>
      <label for="parts">裁切份数：</label>
      <input type="number" id="parts" min="2" value="2">
    </div>
    <button id="splitButton">开始裁切</button>
  </div>
  <script src="popup.js"></script>
</body>
</html>