Harry Theodoulou
將檔案貼入瀏覽器時，需要使用 HTMLElement 的 paste 事件。
使用 HTMLElement 的 paste 事件
首先，您會在所需元素中為 paste 事件新增事件監聽器，這通常位於 document 層級，因此無須聚焦特定元素。接下來，請使用 Clipboard API，藉此存取 HTMLElement paste 事件的 clipboardData 欄位，接著您就可以對其 files 清單進行疊代作業。根據貼上的每個檔案的 MIME 類型，您可以決定要在螢幕上轉譯 (例如圖片或影片)，還是要將檔案的文字內容 (例如在文字檔中) 貼入 textarea 元素。
document.addEventListener('paste', async (e) => {
// Prevent the default behavior, so you can code your own logic.
e.preventDefault();
if (!e.clipboardData.files.length) {
return;
}
// Iterate over all pasted files.
Array.from(e.clipboardData.files).forEach(async (file) => {
// Add more checks here for MIME types you're interested in,
// such as `application/pdf`, `video/mp4`, etc.
if (file.type.startsWith('image/')) {
// For images, create an image and append it to the `body`.
const img = document.createElement('img');
const blob = URL.createObjectURL(file);
img.src = blob;
document.body.append(img);
} else if (file.type.startsWith('text/')) {
// For text files, read the contents and output it into a `textarea`.
const textarea = document.createElement('textarea');
textarea.value = await file.text();
document.body.append(textarea);
}
});
});
其他資訊
示範
HTML
<!DOCTYPE html>
<html>
<head>
<title>How to paste files</title>
</head>
<body>
<h1>How to paste files</h1>
<p>Hit <kbd>⌘</kbd> + <kbd>v</kbd> (for macOS) or <kbd>ctrl</kbd> + <kbd>v</kbd>
(for other operating systems) to paste image or text file(s) anywhere in this page.
</p>
</body>
</html>CSS
html {
box-sizing: border-box;
font-family: system-ui, sans-serif;
color-scheme: dark light;
}
*, *:before, *:after {
box-sizing: inherit;
}
body {
margin: 1rem;
}
img {
height: auto;
max-width: 100%;
display: block;
}
JS
document.addEventListener('paste', async (e) => {
// Prevent the default behavior, so you can code your own logic.
e.preventDefault();
if (!e.clipboardData.files.length) {
return;
}
// Iterate over all pasted files.
Array.from(e.clipboardData.files).forEach(async (file) => {
// Add more checks here for MIME types you're interested in,
// such as `application/pdf`, `video/mp4`, etc.
if (file.type.startsWith('image/')) {
// For images, create an image and append it to the `body`.
const img = document.createElement('img');
const blob = URL.createObjectURL(file);
img.src = blob;
document.body.append(img);
} else if (file.type.startsWith('text/')) {
// For text files, read the contents and output it into a `textarea`.
const textarea = document.createElement('textarea');
textarea.value = await file.text();
document.body.append(textarea);
}
});
});