要显示下载文件的进度条，请查看Jason Niver的博客文章：

Downloading files from the internet in Power Shell (with progress)
基本上，您可以创建一个函数，该函数仍然使用Web客户端功能，但包括一种捕获状态的方法。然后您可以使用WRITE-Progress Power外壳功能向用户显示状态。

function DownloadFile($url, $targetFile)

{

   $uri = New-Object "System.Uri" "$url"

   $request = [System.Net.HttpWebRequest]::Create($uri)

   $request.set_Timeout(15000) #15 second timeout

   $response = $request.GetResponse()

   $totalLength = [System.Math]::Floor($response.get_ContentLength()/1024)

   $responseStream = $response.GetResponseStream()

   $targetStream = New-Object -TypeName System.IO.FileStream -ArgumentList $targetFile, Create

   $buffer = new-object byte[] 10KB

   $count = $responseStream.Read($buffer,0,$buffer.length)

   $downloadedBytes = $count

   while ($count -gt 0)

   {

       $targetStream.Write($buffer, 0, $count)

       $count = $responseStream.Read($buffer,0,$buffer.length)

       $downloadedBytes = $downloadedBytes + $count

       Write-Progress -activity "Downloading file '$($url.split('/') | Select -Last 1)'" -status "Downloaded ($([System.Math]::Floor($downloadedBytes/1024))K of $($totalLength)K): " -PercentComplete ((([System.Math]::Floor($downloadedBytes/1024)) / $totalLength)  * 100)

   }

   Write-Progress -activity "Finished downloading file '$($url.split('/') | Select -Last 1)'"

   $targetStream.Flush()

   $targetStream.Close()

   $targetStream.Dispose()

   $responseStream.Dispose()

}

然后，您只需调用该函数：

downloadFile "http://example.com/largefile.zip" "c:\temp\largefile.zip"

此外，这里还有其他一些来自docs.microsoft for Powrshell7的WRITE-Progress示例。

Write-Progress

在V2中，您可以只使用BitsTransfer模块，例如：

Import-Module BitsTransfer
Start-BitsTransfer https://www.example.com/file C:/Local/Path/file

当我重新编写一些安装脚本时，我遇到了这个问题。这些方法都不是理想的。第一种方法在Windows PowerShell上存在性能问题，第二种方法需要最新的系统，我们都知道它在现实生活中是如何工作的。🤷🏿‍♀️
为了获得尽可能好的性能，我按照PowerShell的最佳实践，将这两种方法合并为一种智能方法，使其更加通用。
可以在here中找到一些基准。

function Get-File
{
    param (
        [Parameter(Mandatory, ValueFromPipelineByPropertyName)]
        [ValidateNotNullOrEmpty()]
        [System.Uri]
        $Uri,
        [Parameter(Mandatory, ValueFromPipelineByPropertyName)]
        [ValidateNotNullOrEmpty()]
        [System.IO.FileInfo]
        $TargetFile,
        [Parameter(ValueFromPipelineByPropertyName)]
        [ValidateNotNullOrEmpty()]
        [Int32]
        $BufferSize = 1,
        [Parameter(ValueFromPipelineByPropertyName)]
        [ValidateNotNullOrEmpty()]
        [ValidateSet('KB, MB')]
        [String]
        $BufferUnit = 'MB',
        [Parameter(ValueFromPipelineByPropertyName)]
        [ValidateNotNullOrEmpty()]
        [ValidateSet('KB, MB')]
        [Int32]
        $Timeout = 10000
    )

    $useBitTransfer = $null -ne (Get-Module -Name BitsTransfer -ListAvailable) -and ($PSVersionTable.PSVersion.Major -le 5)

    if ($useBitTransfer)
    {
        Write-Information -MessageData 'Using a fallback BitTransfer method since you are running Windows PowerShell'
        Start-BitsTransfer -Source $Uri -Destination "$($TargetFile.FullName)"
    }
    else
    {
        $request = [System.Net.HttpWebRequest]::Create($Uri)
        $request.set_Timeout($Timeout) #15 second timeout
        $response = $request.GetResponse()
        $totalLength = [System.Math]::Floor($response.get_ContentLength() / 1024)
        $responseStream = $response.GetResponseStream()
        $targetStream = New-Object -TypeName ([System.IO.FileStream]) -ArgumentList "$($TargetFile.FullName)", Create
        switch ($BufferUnit)
        {
            'KB' { $BufferSize = $BufferSize * 1024 }
            'MB' { $BufferSize = $BufferSize * 1024 * 1024 }
            Default { $BufferSize = 1024 * 1024 }
        }
        Write-Verbose -Message "Buffer size: $BufferSize B ($($BufferSize/("1$BufferUnit")) $BufferUnit)"
        $buffer = New-Object byte[] $BufferSize
        $count = $responseStream.Read($buffer, 0, $buffer.length)
        $downloadedBytes = $count
        $downloadedFileName = $Uri -split '/' | Select-Object -Last 1
        while ($count -gt 0)
        {
            $targetStream.Write($buffer, 0, $count)
            $count = $responseStream.Read($buffer, 0, $buffer.length)
            $downloadedBytes = $downloadedBytes + $count
            Write-Progress -Activity "Downloading file '$downloadedFileName'" -Status "Downloaded ($([System.Math]::Floor($downloadedBytes/1024))K of $($totalLength)K): " -PercentComplete ((([System.Math]::Floor($downloadedBytes / 1024)) / $totalLength) * 100)
        }

        Write-Progress -Activity "Finished downloading file '$downloadedFileName'"

        $targetStream.Flush()
        $targetStream.Close()
        $targetStream.Dispose()
        $responseStream.Dispose()
    }
}

你也可以使用它来获得更快的下载速度和令人印象深刻的进度条。

$fullurl='here put URL of the file which one you want to download'
$BASE_DIR= 'specify the path of the file to be stored '
$useBitTransfer = $null -ne (Get-Module -Name BitsTransfer -ListAvailable) -and ($PSVersionTable.PSVersion.Major -le 5)
if ($useBitTransfer)
    {
        Write-Information -MessageData 'Using a fallback BitTransfer method since you are running Windows PowerShell'
        Start-BitsTransfer -Source $fullUrl -Destination $BASE_DIR\kubescape.exe

    }
    else
    {
       Invoke-WebRequest -Uri $fullUrl -OutFile $BASE_DIR\kubescape.exe
    }

这是一个老问题，但我有一个很好的解决方案。

$webClient = New-Object -TypeName System.Net.WebClient
$webClient.Credentials = $login
$task = $webClient.DownloadFileTaskAsync($uri, $PSScriptRoot + "\" + $asset)

Register-ObjectEvent -InputObject $webClient -EventName DownloadProgressChanged -SourceIdentifier WebClient.DownloadProgressChanged | Out-Null

Start-Sleep -Seconds 3

while (!($task.IsCompleted)) {
    $EventData = Get-Event -SourceIdentifier WebClient.DownloadProgressChanged | Select-Object -ExpandProperty "SourceEventArgs" -Last 1

    $ReceivedData = ($EventData | Select-Object -ExpandProperty "BytesReceived")
    $TotalToReceive = ($EventData | Select-Object -ExpandProperty "TotalBytesToReceive")
    $TotalPercent = $EventData | Select-Object -ExpandProperty "ProgressPercentage"

    Start-Sleep -Seconds 2

    Write-Progress -Activity "Downloading File" -Status "Percent Complete: $($TotalPercent)%" -CurrentOperation "Downloaded $(convertFileSize -bytes $ReceivedData) / $(convertFileSize -bytes $TotalToReceive)" -PercentComplete $TotalPercent
}

Unregister-Event -SourceIdentifier WebClient.DownloadProgressChanged
$webClient.Dispose()

现在，您还需要一个函数来转换文件大小：

function convertFileSize {
    param(
        $bytes
    )

    if ($bytes -lt 1MB) {
        return "$([Math]::Round($bytes / 1KB, 2)) KB"
    }
    elseif ($bytes -lt 1GB) {
        return "$([Math]::Round($bytes / 1MB, 2)) MB"
    }
    elseif ($bytes -lt 1TB) {
        return "$([Math]::Round($bytes / 1GB, 2)) GB"
    }
}

我从Invoke-DownloadFile获取代码片段。功劳归于蒂姆·斯莫尔。