pdf 小程序 base64

要将一个 PDF 文件转换为 base64 编码的字符串，可以使用 JavaScript 中的 FileReader 和 btoa 函数。

以下是一个简单的示例代码：

// 读取 PDF 文件
const fileReader = new FileReader();
fileReader.readAsDataURL(pdfFile);

// 当文件读取完成时执行回调函数
fileReader.onload = () => {
  // 将文件内容转换为 base64 编码的字符串
  const base64String = btoa(fileReader.result);

  // 将 base64 编码的字符串作为参数传递给小程序 API
  // 例如 wx.request 或 wx.uploadFile
  // ...
};

其中，`pdfFile` 是一个 File 对象，表示要转换的 PDF 文件。在小程序中，可以通过 `wx.chooseMessageFile` 或 `wx.chooseImage` 等 API 获取用户选择的文件。

相关问题

小程序解码base64PDF

import base64

# 将base64编码的PDF文件解码
base64_pdf = b'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

微信小程序开发pdf

微信小程序开发中，可以通过一些工具和技术来生成 PDF 文件。以下是一种简单的方法：

1. 在小程序中引入一个用于生成 PDF 的第三方库，例如 pdfmake 或 pdfkit。
2. 在小程序的页面中，通过调用该库的相关方法来生成 PDF 文件。
3. 需要注意的是，在小程序中无法直接将 PDF 文件保存到本地，但可以通过 base64 编码的方式将 PDF 文件转换为数据流，并传输到服务器端。
4. 在服务器端，可以将接收到的数据流解码，并保存为 PDF 文件。

需要注意的是，由于小程序的限制和安全性考虑，使用第三方库生成 PDF 文件可能会有一些限制和局限性。此外，还需要确保遵守相关法律法规，在合规的前提下使用这些技术。