使用PowerShell的HttpClient下载1.3GB文件时触发‘任务已取消’错误

问题重现 #

尝试通过PowerShell调用.NET HttpClient对象（而非Invoke-RestMethod）下载1.3GB的ISO文件，编写代码如下：

using namespace System.Net.Http

$username = "joedirt"
$password = "mypassword"
$baseUrl = "https://mywebsite.com/artifactory/api/storage/"
$repository = "my-repo"
$path = "filename.iso"
$outputFilePath = "C:\Users\joedirt\Downloads\filename.iso"

$httpClient = [System.Net.Http.HttpClient]::new()
$uri = [System.Uri]::new(($baseUrl, $repository, $path -join '/'))

$httpClient.DefaultRequestHeaders.Authorization = [System.Net.Http.Headers.AuthenticationHeaderValue]::new(
    "Basic",
    [System.Convert]::ToBase64String(
        [System.Text.Encoding]::ASCII.GetBytes(
            ($username + ":" + $password)
        )
    )
)

$response = $httpClient.GetAsync($uri).GetAwaiter().GetResult()

if ($response.IsSuccessStatusCode){
    $fileStream = [System.IO.FileStream]::new($outputFilePath, [System.IO.FileMode]::Create, [System.IO.FileAccess]::Write, [System.IO.FileShare]::None)
    $responseStream = $response.Content.ReadAsStreamAsync().GetAwaiter().GetResult()
    $buffer = [byte[]]::new(8192)
    while (([int]$bytesRead = $responseStream.Read($buffer, 0, $buffer.Length)) -gt 0){
        $fileStream.Write($buffer, 0, $bytesRead)
    }
    [System.Console]::WriteLine("File downloaded successfully.")
} else {
    [System.Console]::WriteLine("Failed to download file. StatusCode: $($response.StatusCode)")
}

执行到$response = $httpClient.GetAsync($uri).GetAwaiter().GetResult()时，程序停顿数分钟后抛出错误：

Exception calling "GetResult" with "0" argument(s): "A task was canceled."

但使用Invoke-RestMethod从同一URL可以正常下载该文件。

解决方案 #

问题根源是HttpClient默认超时时间（100秒）不足以完成1.3GB大文件的下载，只需调整超时时间即可解决：

在初始化HttpClient后添加超时配置：

$httpClient.Timeout = [System.TimeSpan]::new(0, 20, 0) # 设置为20分钟

调整后即可成功完成大文件下载。

内容的提问来源于stack exchange，提问作者jerdub1993