PowerShell Export-Csv 在输出中重复最后一个值 - 解决方案

Question

场景： 在我的脚本中，我创建一个对象，添加公共信息，然后在循环中更新每个对象的子信息，并将该对象添加到对象数组中。 我的详细说明显示添加到数组的对象中的值是正确的（报告数组中的最后一项），但 Export-Csv 重复最后一个对象值。 如果我每次都创建一个新对象，我就能解决这个问题。重复使用同一个对象会重复最后一个值，即使当我在数组中的对象上选择 * 时我可以看到它是正确的。数组对象必须有一些东西，例如为同一对象复制的 guid。 PowerShell 5.1 在 Windows 7、Windows 2008R2、Windows 2010R2 上验证

解决方案： 将对象添加到对象数组时不要重用它。

输出：

#TYPE MyGpoSetting
"SetName","SetCategory","SetType","SetState","SetValue","SetData","SetNote","SubName","SubState","SubValue","GpoDomain","GpoName","GpoLinks","GpoGuid"
"SetName","SetCategory","SetType","SetState","SetValue","SetData","SetNote","SubName3","SubState3","SubValue3","GpoDomain","GpoName","GpoLinks","GpoGuid"
"SetName","SetCategory","SetType","SetState","SetValue","SetData","SetNote","SubName3","SubState3","SubValue3","GpoDomain","GpoName","GpoLinks","GpoGuid"
"SetName","SetCategory","SetType","SetState","SetValue","SetData","SetNote","SubName3","SubState3","SubValue3","GpoDomain","GpoName","GpoLinks","GpoGuid"

脚本：

Add-Type -TypeDefinition @"
   public struct MyGpoSetting
   {
      public string  SetName;
      public string  SetCategory;
      public string  SetType;
      public string  SetState;
      public string  SetValue;
      public string  SetData;
      public string  SetNote;
      public string  SubName;
      public string  SubState;
      public string  SubValue;
      public string  GpoDomain;
      public string  GpoName;
      public string  GpoLinks;
      public string  GpoGuid;
   }
"@
$aoMyGpoSetting = @();
$oMyGpoSetting = New-Object -TypeName 'MyGpoSetting';
$oMyGpoSetting.SetName       = 'SetName';
$oMyGpoSetting.SetCategory   = 'SetCategory';
$oMyGpoSetting.SetType       = 'SetType';
$oMyGpoSetting.SetState      = 'SetState';
$oMyGpoSetting.SetValue      = 'SetValue';
$oMyGpoSetting.SetData       = 'SetData';
$oMyGpoSetting.SetNote       = 'SetNote';
$oMyGpoSetting.SubName       = 'SubName1';
$oMyGpoSetting.SubState      = 'SubState1';
$oMyGpoSetting.SubValue      = 'SubValue1';
$oMyGpoSetting.GpoDomain     = 'GpoDomain';
$oMyGpoSetting.GpoName       = 'GpoName';
$oMyGpoSetting.GpoLinks      = 'GpoLinks';
$oMyGpoSetting.GpoGuid       = 'GpoGuid';
$aoMyGpoSetting += $oMyGpoSetting;
#--- $oMyGpoSetting = New-Object -TypeName 'MyGpoSetting';
$oMyGpoSetting.SetName       = 'SetName';
$oMyGpoSetting.SetCategory   = 'SetCategory';
$oMyGpoSetting.SetType       = 'SetType';
$oMyGpoSetting.SetState      = 'SetState';
$oMyGpoSetting.SetValue      = 'SetValue';
$oMyGpoSetting.SetData       = 'SetData';
$oMyGpoSetting.SetNote       = 'SetNote';
$oMyGpoSetting.SubName       = 'SubName2';
$oMyGpoSetting.SubState      = 'SubState2';
$oMyGpoSetting.SubValue      = 'SubValue2';
$oMyGpoSetting.GpoDomain     = 'GpoDomain';
$oMyGpoSetting.GpoName       = 'GpoName';
$oMyGpoSetting.GpoLinks      = 'GpoLinks';
$oMyGpoSetting.GpoGuid       = 'GpoGuid';
$aoMyGpoSetting += $oMyGpoSetting;
#--- $oMyGpoSetting = New-Object -TypeName 'MyGpoSetting';
$oMyGpoSetting.SetName       = 'SetName';
$oMyGpoSetting.SetCategory   = 'SetCategory';
$oMyGpoSetting.SetType       = 'SetType';
$oMyGpoSetting.SetState      = 'SetState';
$oMyGpoSetting.SetValue      = 'SetValue';
$oMyGpoSetting.SetData       = 'SetData';
$oMyGpoSetting.SetNote       = 'SetNote';
$oMyGpoSetting.SubName       = 'SubName3';
$oMyGpoSetting.SubState      = 'SubState3';
$oMyGpoSetting.SubValue      = 'SubValue3';
$oMyGpoSetting.GpoDomain     = 'GpoDomain';
$oMyGpoSetting.GpoName       = 'GpoName';
$oMyGpoSetting.GpoLinks      = 'GpoLinks';
$oMyGpoSetting.GpoGuid       = 'GpoGuid';
$aoMyGpoSetting += $oMyGpoSetting;
$aoMyGpoSetting | Export-Csv -Path 'c:\temp\export.csv' -Encoding 'ASCII';

Answer 1

这是按预期工作的。将对象添加到数组 (+=) 不会复制对象，而是在下一个“插槽”中添加指向它的引用/指针。因此，实际上您正在添加对同一对象的三个引用。这就像在您最好的朋友的电话簿中有 3 个条目：

John Smith - 01234 5678
Jonnie - 01234 5678
Smith, John - 01234 5678

无论您打电话给哪个人，都会让您接通完全相同的人。

同样，每次 PowerShell 从您的数组中显示一个对象时，它实际上都会返回到同一个源对象并将其显示给您。这就是为什么它们都具有与您添加的最后一个相同的属性的原因 - 它们实际上都是相同的。

正如您所发现的，每次都创建一个新对象是继续的方法。