使用 System.Net.WebClient.DownloadFile 下载文件时显示已损坏

Question

I uploaded a file to a cloud which gives me direct download link.

Downloading it by clicking on this link works fine, but when I try to download it via System.Net.WebClient.DownloadFile on Powershell, it downloads the file, but when I open it it says that the file is corrupted and unreadable .

That's the code:

$WebClient = New-Object System.Net.WebClient
$WebClient.DownloadFile("https://xxxxxx.com/xxxxx/xxx.exe","C:\Users\user\Desktop\xxx.exe")

Any solution?

Answer 1

Strange, this logic works for me.

You could try adding $WebClient.Dispose() ?

or other PowerShell download methods such as:

$uri = "https://xxxxxx.com/xxxxx/xxx.exe"
$path = "C:\Users\user\Desktop\xxx.exe"

Invoke-WebRequest -Uri $uri -OutFile $path

Answer 2

3 ways to download files with PowerShell

<#
# 1. Invoke-WebRequest

The first and most obvious option is the Invoke-WebRequest cmdlet. It is built
into PowerShell and can be used in the following method:
#>

$url = "http://mirror.internode.on.net/pub/test/10meg.test"
$output = "$PSScriptRoot\10meg.test"
$start_time = Get-Date
Invoke-WebRequest -Uri $url -OutFile $output
Write-Output "Time taken: $((Get-Date).Subtract($start_time).Seconds) second(s)"

<#
2. System.Net.WebClient

A common .NET class used for downloading files is the System.Net.WebClient class.
#>

$url = "http://mirror.internode.on.net/pub/test/10meg.test"
$output = "$PSScriptRoot\10meg.test"
$start_time = Get-Date
$wc = New-Object System.Net.WebClient
$wc.DownloadFile($url, $output)

# OR

(New-Object System.Net.WebClient).DownloadFile($url, $output)
Write-Output "Time taken: $((Get-Date).Subtract($start_time).Seconds) second(s)"

<#
3. Start-BitsTransfer

If you haven't heard of BITS before, check this out. BITS is primarily designed
for asynchronous file downloads, but works perfectly fine synchronously too
(assuming you have BITS enabled).
#>

$url = "http://mirror.internode.on.net/pub/test/10meg.test"
$output = "$PSScriptRoot\10meg.test"
$start_time = Get-Date
Import-Module BitsTransfer
Start-BitsTransfer -Source $url -Destination $output

# Or

Start-BitsTransfer -Source $url -Destination $output -Asynchronous
Write-Output "Time taken: $((Get-Date).Subtract($start_time).Seconds) second(s)"

Here is what I personally use daily, from a function in my personal module imported via my profile.

$webclient = New-Object System.Net.WebClient
$url       = 'https://download.microsoft.com/download/B/A/4/BA4A7E71-2906-4B2D-A0E1-80CF16844F5F/dotNetFx45_Full_setup.exe'

$filename = [System.IO.Path]::GetFileName($url)
$file     = "$TechToolsUNC\$filename"

$webclient.DownloadFile($url,$file)
Start-Process $file -Wait

Answer 3

I would speculate that his is not about powershell, but other factors on your machine or network, most likely antivirus agent etc.