将非托管结构编组为 C#

Question

如何将这个非托管结构转换为 C#。

typedef struct _EC_VARIANT {
  union {
    BOOL                            BooleanVal;
    UINT32                          UInt32Val;
    ULONGLONG                       DateTimeVal;
    LPCWSTR                         StringVal;
    PBYTE                           BinaryVal;
    BOOL                            *BooleanArr;
    INT32                           *Int32Arr;
    LPWSTR                          *StringArr;
    EC_OBJECT_ARRAY_PROPERTY_HANDLE PropertyHandleVal;
  };
  DWORD Count;
  DWORD Type;
} EC_VARIANT, *PEC_VARIANT;

文档：https://learn.microsoft.com/ru-ru/windows/win32/api/evcoll/ns-evcoll-ec_variant 我尝试这个代码：

uint get = Internals.EcOpenSubscription("adfs", (uint)WecAcessTypes.EC_READ_ACCESS, (uint)WecFlags.EC_OPEN_EXISTING);
Console.WriteLine($"addr :{get}");
byte[] some = new byte[16];
uint a = 0;
bool success = Internals.EcGetSubscriptionProperty(get, (uint)EC_SUBSCRIPTION_PROPERTY_ID.EcSubscriptionEventSources, 0, 128, some, out a);
if (!success)
{
    Console.WriteLine("err EcSubscriptionEventSources");
    Console.ReadKey();
    return;
}
foreach (byte b in some)
{
    Console.Write(b);
}
GCHandle gCHandle = GCHandle.Alloc(some, GCHandleType.Pinned);
EC_VARIANT eC = (EC_VARIANT)Marshal.PtrToStructure(gCHandle.AddrOfPinnedObject(), typeof(EC_VARIANT));
Console.WriteLine($"\n{eC.Type} {eC.EC_OBJECT_ARRAY_PROPERTY_HANDLE}");
Console.WriteLine($"length {a}");
Console.ReadKey();

我的结构：

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct EC_VARIANT
{
    public uint BooleanVal;
    public uint UInt32Val;
    public ulong DateTimeVal;
    public IntPtr StringVal;
    public IntPtr BinaryVal;
    public IntPtr BoolArr;
    public IntPtr Int32Arr;
    public IntPtr StringArr;
    public int EC_OBJECT_ARRAY_PROPERTY_HANDLE;
    public int Type;
    public int Count;
}

我尝试使用 LayoutKind.Explicit 并以不同的方式排列字段，但无济于事

Answer 1

您可以使用

CsWin32

源生成器来获取相关函数/结构/枚举/等的所有定义。

使用方法：

• 安装

  CsWin32

  nuget 包：

  dotnet add package Microsoft.Windows.CsWin32

  或

  Install-Package Microsoft.Windows.CsWin32

• 将

  NativeMethods.txt

  文件添加到项目的根目录中（与

  .csproj

  位于同一文件夹中）。

• 将以下内容放入

  NativeMethods.txt

  ：

  EC_VARIANT
  EcGetSubscriptionProperty
  EcOpenSubscription
  EC_*
  EC_VARIANT_TYPE
  

  这将告诉生成器为所有列出的实体生成定义。

• 在您的代码中使用如下（我重写了您的示例并稍微简化了它）。

    using Windows.Win32.System.EventCollector;
    using static Windows.Win32.PInvoke;
  
    var get = EcOpenSubscription("adfs", EC_READ_ACCESS, EC_OPEN_EXISTING);
    Console.WriteLine($"addr :{get}");
    var some = new EC_VARIANT();
    var success = EcGetSubscriptionProperty(get,
        EC_SUBSCRIPTION_PROPERTY_ID.EcSubscriptionEventSources, 0, 128,
        ref some, out var used);
  
    if (!success)
    {
        Console.WriteLine("Failed to get subscription property");
        return;
    }
  
    Console.WriteLine($"Type: {some.Type}");
    var union = some.Anonymous;
    var strVal = (EC_VARIANT_TYPE)some.Type switch
    {
        EC_VARIANT_TYPE.EcVarTypeNull => "null",
        EC_VARIANT_TYPE.EcVarTypeBoolean => union.BooleanVal.ToString(),
        EC_VARIANT_TYPE.EcVarTypeUInt32 => union.UInt32Val.ToString(),
        EC_VARIANT_TYPE.EcVarTypeDateTime => union.DateTimeVal.ToString(),
        EC_VARIANT_TYPE.EcVarTypeString => union.StringVal.ToString(),
        EC_VARIANT_TYPE.EcVarObjectArrayPropertyHandle => union.PropertyHandleVal.ToString(),
        _ => throw new ArgumentOutOfRangeException()
    };
    Console.WriteLine($"Value: {strVal}");