为什么我从 powershell 上传到 ftp 得到的是空白文件

Question

我得到了这个教程 FTP 上传

#Unique Variables
$FTPServer = "ftp://example.com/"
$FTPUsername = "username"
$FTPPassword = "password" 
$LocalDirectory = "C:\temp\" 
$FileToUpload = "example.txt"

#Connect to the FTP Server
$ftp = [System.Net.FtpWebRequest]::create("$FTPServer/$FileToUpload")
$ftp.Credentials =  New-Object System.Net.NetworkCredential($FTPUsername,$FTPPassword)

#Upload file to FTP Server
$ftp.Method = [System.Net.WebRequestMethods+Ftp]::UploadFile

#Verify the file was uploaded
$ftp.GetResponse()

但在我的 ftp 上我只得到空白文件，为什么？