unsafeな構造体をマーシャリングを使ってunsafeでない構造体にし、DeviceIoControl関数にて使用しようとしていますが２度目のアクセス時に文字列データが文字化けしてしまいます。どうしたらいいでしょうか？(unsafe版は正常に動作しています。)
＜構造体の宣言＞
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public class HostControllerDriverKeyName
{
public uint ActualLength;
[MarshalAs(UnmanagedType.LPWStr)]
public string Name;
}
＜コード＞
HostControllerDriverKeyName valKeyName = new HostControllerDriverKeyName();
int nReturned = Marshal.SizeOf(valKeyName);
IntPtr ptrKeyName = Marshal.AllocCoTaskMem(nReturned);
if (!DevIOCtl.DeviceIoControl(hHostController,
DevIOCtl.ControlCode.USBHcdGetDriverKeyName,
IntPtr.Zero,
0,
ptrKeyName,
nReturned,
ref nReturned,
IntPtr.Zero))
{
Marshal.FreeCoTaskMem(ptrKeyName);
return null;
}
nReturned = Marshal.ReadInt32(ptrKeyName);
if (nReturned <= Marshal.SizeOf(valKeyName))
{
Marshal.FreeCoTaskMem(ptrKeyName);
return null;
}
ptrKeyName = Marshal.ReAllocCoTaskMem(ptrKeyName, nReturned);
if (ptrKeyName == IntPtr.Zero)
{
Marshal.FreeCoTaskMem(ptrKeyName);
return null;
}
if (!DevIOCtl.DeviceIoControl(hHostController,
DevIOCtl.ControlCode.USBHcdGetDriverKeyName,
IntPtr.Zero,
0,
ptrKeyName,
nReturned,
ref nReturned,
IntPtr.Zero))
{
Marshal.FreeCoTaskMem(ptrKeyName);
return null;
}
Marshal.PtrToStructure(ptrKeyName, valKeyName);
Marshal.FreeCoTaskMem(ptrKeyName);
return valKeyName.Name;
