c# - 如何在 C# 中调用 GetVirtualDiskInformation

Question

完整的极简主义(非工作)代码:http://pastebin.com/GPdSxyrt

我正在尝试 PInvoke GetVirtualDiskInformation ( https://msdn.microsoft.com/en-us/library/windows/desktop/dd323670(v=vs.85).aspx ) 并使用我的代码:

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct GetVirtualDiskInfo
{
    public GetVirtualDiskInfoVersion Version; //GET_VIRTUAL_DISK_INFO_VERSION
    public GetVirtualDiskInfoUnion Union;
}

[StructLayout(LayoutKind.Explicit, CharSet = CharSet.Unicode)]
public struct GetVirtualDiskInfoUnion
{
    [FieldOffset(0)] public GetVirtualDiskInfoSize Size;
    [FieldOffset(0)] public Guid Identifier; //GUID
    [FieldOffset(0)] public GetVirtualDiskInfoParentLocation ParentLocation;
    [FieldOffset(0)] public Guid ParentIdentifier; //GUID
    [FieldOffset(0)] public uint ParentTimestamp; //ULONG
    [FieldOffset(0)] public VirtualStorageType VirtualStorageType; //VIRTUAL_STORAGE_TYPE
    [FieldOffset(0)] public uint ProviderSubtype; //ULONG
    [FieldOffset(0)] public bool Is4kAligned; //BOOL
    [FieldOffset(0)] public bool IsLoaded; //BOOL
    [FieldOffset(0)] public GetVirtualDiskInfoPhysicalDisk PhysicalDisk;
    [FieldOffset(0)] public uint VhdPhysicalSectorSize; //ULONG
    [FieldOffset(0)] public ulong SmallestSafeVirtualSize; //ULONGLONG
    [FieldOffset(0)] public uint FragmentationPercentage; //ULONG
    [FieldOffset(0)] public Guid VirtualDiskId; //GUID
    [FieldOffset(0)] public GetVirtualDiskInfoChangeTrackingState ChangeTrackingState;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct GetVirtualDiskInfoSize
{
    public ulong VirtualSize; //ULONGLONG
    public ulong PhysicalSize; //ULONGLONG
    public uint BlockSize; //ULONG
    public uint SectorSize; //ULONG
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct GetVirtualDiskInfoParentLocation
{
    public bool ParentResolved; //BOOL
    public char ParentLocationBuffer; //WCHAR[1] //TODO
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct GetVirtualDiskInfoPhysicalDisk
{
    public uint LogicalSectorSize; //ULONG
    public uint PhysicalSectorSize; //ULONG
    public bool IsRemote; //BOOL
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct GetVirtualDiskInfoChangeTrackingState
{
    public bool Enabled; //BOOL
    public bool NewerChanges; //BOOL
    public char MostRecentId; //WCHAR[1] //TODO
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct VirtualStorageType
{
    public VirtualStorageDeviceType DeviceId; //ULONG
    public Guid VendorId; //GUID
}

public enum GetVirtualDiskInfoVersion
{
    Unspecified = 0,
    Size = 1,
    Identifier = 2,
    ParentLocation = 3,
    ParentIdentifier = 4,
    ParentTimestamp = 5,
    VirtualStorageType = 6,
    ProviderSubtype = 7,
    Is4KAligned = 8,
    PhysicalDisk = 9,
    VhdPhysicalSectorSize = 10,
    SmallestSafeVirtualSize = 11,
    Fragmentation = 12,
    IsLoaded = 13,
    VirtualDiskId = 14,
    ChangeTrackingState = 15
}

public enum VirtualStorageDeviceType
{
    Unknown = 0,
    Iso = 1,
    Vhd = 2,
    Vhdx = 3,
    Vhdset = 4
}

[DllImport("virtdisk.dll", CharSet = CharSet.Unicode)]
public static extern uint GetVirtualDiskInformation
(
    [In]            VirtualDiskSafeHandle virtualDiskHandle,
    [In, Out]   ref uint virtualDiskInfoSize,
    [In, Out]   ref GetVirtualDiskInfo virtualDiskInfo,
    [In, Out]   ref uint sizeUsed
);

我这样调用 GetVirtualDiskInformation:

var info = new GetVirtualDiskInfo {Version = infoVersion};
infoSize = (uint) Marshal.SizeOf(info);
var result = NativeMethods.GetVirtualDiskInformation(handle, ref infoSize, ref info, ref sizeUsed);

显然 handle 确实包含一个有效的 VirtualDiskSafeHandle 在这里。

问题是我的输出结构完全搞砸了。数据无处不在。例如，根据它，VHD 的 LogicalSectorSize 为 257，它有一个负的 VirtualSize。

我哪里做错了，我怎样才能让它正常工作？

编辑:

错误的具体例子:

我创建了一个全新的 VHDX 作为差异(无父级，无源)，将其最大大小设置为 50MB，LogicalSectorSize 为 512，PhysicalSectorSize 为 4096，BlockSize 到 2MB，它是 VendorId (GUID) 到 new Guid("EC984AEC-A0F9-47e9-901F-71415A66345B")。它从未被附加，它在磁盘上的大小恰好为 4096KB。

我期望在执行时:

var info = new GetVirtualDiskInfo {Version = GetVirtualDiskInfoVersion.Size};
infoSize = (uint) Marshal.SizeOf(info);
var result = NativeMethods.GetVirtualDiskInformation(handle, ref infoSize, ref info, ref sizeUsed);

info.Union.Size 将返回:

VirtualSize = 52428800
PhysicalSize = 4194304
BlockSize = 2097152
SectorSize = 512

我得到的是“足够接近”。除了 VirtualSize 之外的所有值都是正确的，它返回 52428801。现在额外的一个字节可能是预期的，但我对此表示怀疑。无论如何，接下来的几个例子会产生更糟糕的结果:

var info = new GetVirtualDiskInfo {Version = GetVirtualDiskInfoVersion.VirtualStorageType};
infoSize = (uint) Marshal.SizeOf(info);
var result = NativeMethods.GetVirtualDiskInformation(handle, ref infoSize, ref info, ref sizeUsed);

info.Union.VirtualStorageType 的预期结果:

DeviceId = 2 //2 Symbolizes VHDX, which is how I created it
VendorId = "EC984AEC-A0F9-47e9-901F-71415A66345B" //As a GUID

实际结果:

DeviceId = 257
VendorId = "EC984AEC-A0F9-47e9-901F-71415A66345B" //As a GUID

换句话说，GUID 可以，DeviceId 不行。 257 甚至不是有效值。

最后一个例子:

var info = new GetVirtualDiskInfo {Version = GetVirtualDiskInfoVersion.PhysicalDisk};
infoSize = (uint) Marshal.SizeOf(info);
var result = NativeMethods.GetVirtualDiskInformation(handle, ref infoSize, ref info, ref sizeUsed);

预期 info.Union.PhysicalDisk 返回:

LogicalSectorSize = 512
PhysicalSectorSize = 4096
IsRemote = false

实际结果:

LogicalSectorSize  = 257
PhysicalSectorSize = 512
IsRemote = false

所以第一个值又是完全错误的。 257 不是可接受的值，第二个值也是错误的，我希望是 4096。

EDIT2 将 VirtualStorageDeviceType 添加到初始代码。

EDIT3 完整示例在这里:http://pastebin.com/GPdSxyrt

EDIT4

我发现问题出在 C 中的字段是 WCHAR[1]。如果我在结构 GetVirtualDiskInfoUnion 中注释掉 ChangeTrackingState，那么一切正常。

仍然，我不确定在 C# 中如何设置它们，它们似乎不是 char 也不是 IntPtr 我试过的，那怎么办准确翻译成？

Answer 1

我没有解决方案，但注意到如果您在结构的最后添加任何 uint 字段，它也可以正常工作。我的定义是:

公共(public)结构 GetVirtualDiskInfoUnion
{
[FieldOffset(0)] public GetVirtualDiskInfoSize 大小；
[FieldOffset(0)] 公共(public) Guid 标识符；//GUID
[FieldOffset(0)] public GetVirtualDiskInfoParentLocation ParentLocation;
[FieldOffset(0)] public Guid ParentIdentifier;//GUID
[FieldOffset(0)] public uint ParentTimestamp;//乌龙
[FieldOffset(0)] public VirtualStorageType VirtualStorageType;//虚拟存储类型
[FieldOffset(0)] public uint ProviderSubtype;//乌龙
[FieldOffset(0)] public bool Is4kAligned;// bool 值
[FieldOffset(0)] public bool IsLoaded;// bool 值
[FieldOffset(0)] public GetVirtualDiskInfoPhysicalDisk PhysicalDisk;
[FieldOffset(0)] public uint VhdPhysicalSectorSize;//乌龙
[FieldOffset(0)] public ulong SmallestSafeVirtualSize;//乌隆隆
[FieldOffset(0)] public uint FragmentationPercentage;//乌龙
[FieldOffset(0)] public Guid VirtualDiskId;//GUID
[FieldOffset(0)] public GetVirtualDiskInfoChangeTrackingState ChangeTrackingState;
[FieldOffset(0)] public uint 保留；//乌龙