Question

我试图确定一个StreamWriter对象是否在脚本中打开或已经关闭。如果它没有关闭，我可以在文件中写一个新行。如果关闭，我需要执行其他操作....

如何验证流是否仍处于打开状态？

示例测试脚本。

$stream = [System.IO.StreamWriter] "C:\testing.txt"
$stream.WriteLine("TEST")
$stream.close()
if($stream)){
    #stream still open, write new line
    $stream.WriteLine("Stream is still open.  Write.")
    $stream.close()
}else(
    #stream not open... end script, send reponse.
}

Answer 1

您可以检查BaseStream - 对象是否存在Streamwriter。像这样：

if($stream.BaseStream)){
    #Stream is open
}

示例：

$sw = New-Object System.IO.StreamWriter "C:\test.txt"

PS > $sw | fl *


AutoFlush      : False
BaseStream     : System.IO.FileStream
Encoding       : System.Text.UTF8Encoding
FormatProvider : nb-NO
NewLine        : 

PS > if($sw.BaseStream) { "yes" }
yes

PS > $sw.Close()

PS > if($sw.BaseStream) { "yes" }

PS > $sw


AutoFlush      : False
BaseStream     : 
Encoding       : 
FormatProvider : nb-NO
NewLine        :

编辑或者您可以查看其中一项：

if($sw.BaseStream.CanWrite) {
    #You have permission to write = stream open and writeable
    }

#or

if($sw.BaseStream.SafeFileHandle) {
    #you have a filehandle = stream open
    }

是否有方法来确定System.IO.StreamWriter对象是否已打开？

1 个答案: