从 C# 在 Hyper-V WMI V2 中应用快照

Question

我正在尝试在 C# 中复制以下 PowerShell：

# Details from here are not particularly important but needed for full sample
$vms = gwmi -namespace "root\virtualization\v2" Msvm_ComputerSystem
$vm = $vms[3]
$snapshot = ($vm.GetRelated("Msvm_VirtualSystemSettingData") | Where { $_.ElementName -eq "SnapshotName" })[0]
# end unimportant 

$VMSS = Get-WMiObject -class Msvm_VirtualSystemSnapshotService -namespace root\virtualization\v2
$VMSS.ApplySnapshot($snapshot, $null)

此代码运行良好 - 快照按预期应用。

在 C# 中获取 Msvm_VirtualSystemSettingData 实例或 Msvm_VirtualSystemSnapshostService 实例没有问题。但是，我似乎无法正确拨打ApplySnapshot 的电话——无论我给它什么，我都会得到InvalidOperationException。我正在使用 Visual Studio 生成的 WMI 代码进行调用：

public uint ApplySnapshot(ref System.Management.ManagementPath Job, System.Management.ManagementPath Snapshot) {
    if ((isEmbedded == false)) {
        System.Management.ManagementBaseObject inParams = null;
        inParams = PrivateLateBoundObject.GetMethodParameters("ApplySnapshot");
        // following line has been through variations as well with no change -
        // commenting it out, setting to null
        inParams["Job"] = ((System.Management.ManagementPath)(Job)).Path;
        inParams["Snapshot"] = ((System.Management.ManagementPath)(Snapshot)).Path;
        System.Management.ManagementBaseObject outParams = PrivateLateBoundObject.InvokeMethod("ApplySnapshot", inParams, null);
        Job = ((System.Management.ManagementPath)(outParams.Properties["Job"].Value));
        return System.Convert.ToUInt32(outParams.Properties["ReturnValue"].Value);
    }
    else {
        return System.Convert.ToUInt32(0);
    }
}

我也不确定要为 Job 参数传递什么，因为我们得到了一份工作 - 使用 ref 而不是 out 是非常不寻常的，但我已经尝试了很多围绕它的不同变化（包括将参数设置为null 并且根本不设置它）没有运气。我也尝试将inParams[Job] 设置为null，但也没有运气。

我应该改变什么来完成这项工作？

Answer 1

我相信您的问题是，当它是出站参数时，您正在传递作业以开始。该参数将从调用中返回。有点像..

ManagementBaseObject inParams = null;

inParams = PrivateLateBoundObject.GetMethodParameters("ApplySnapshot");
inParams["Snapshot"] = ((System.Management.ManagementPath)(Snapshot)).Path;

ManagementBaseObject outParams = PrivateLateBoundObject.InvokeMethod("ApplySnapshot", inParams, null);

// i left this as i assume this is vs generated though this isn't how i would normally
// get my jobs back.
Job = ((ManagementPath)(outParams.Properties["Job"].Value));

return Convert.ToUInt32(outParams.Properties["ReturnValue"].Value);