ContentService用于将文本内容作为Web应用程序提供。你所显示的代码行并不是它自己的。假设它是您作为Web App部署的 doGet（）函数的一行代码，那么这就是为什么您看不到任何内容：

ContentService is used to serve up text content as a Web Application. The line of code you've shown does nothing on it's own. Assuming that it's a one-line body of a doGet() function that you've deployed as a Web App, then here's why you're seeing nothing:

• ContentService - 使用内容服务和...


• .createTextOutput（） - 创建一个空的文本输出对象，然后...


• .downloadAsFile（fileName） - 当浏览器调用我们的 Get 服务时，请下载内容（名为 fileName ）而不是显示它。

• ContentService - use Content Service, and...
• .createTextOutput() - create an empty text output object, then...
• .downloadAsFile(fileName) - when a browser invokes our Get service, have it download the content (named fileName) rather than displaying it.

由于我们没有内容，没有什么可以下载，所以你看，没有任何。

Since we have no content, there's nothing to download, so you see, well, nothing.

此脚本将在您的Google云端硬盘上获取csv文件的文本内容，并将其提供下载。一旦您保存了该版本的脚本并将其发布为网络应用程序，您可以将浏览器引导到发布的URL来开始下载。

This script will get the text content of a csv file on your Google Drive, and serve it for downloading. Once you've saved a version of the script and published it as a web app, you can direct a browser to the published URL to start a download.

根据您的浏览器设置，您可能可以选择特定的本地文件夹和/或更改文件名。您无法从服务器端运行此脚本。

Depending on your browser settings, you may be able to select a specific local folder and/or change the file name. You have no control over that from the server side, where this script runs.

/**
 * This function serves content for a script deployed as a web app.
 * See https://developers.google.com/apps-script/execution_web_apps
 */
function doGet() {
  var fileName = "test.csv"
  return ContentService
            .createTextOutput()            // Create textOutput Object
            .append(getCsvFile(fileName))  // Append the text from our csv file
            .downloadAsFile(fileName);     // Have browser download, rather than display
}    

/**
 * Return the text contained in the given csv file.
 */
function getCsvFile(fileName) {
  var files = DocsList.getFiles();
  var csvFile = "No Content";

  for (var i = 0; i < files.length; i++) {
    if (files[i].getName() == fileName) {
      csvFile = files[i].getContentAsString();
      break;
    }
  }
  return csvFile
}