.NET Framework 封送处理结构
示例
简单的结构
C++签名：
typedef struct _PERSON
{
int age;
char name[32];
} PERSON, *LP_PERSON;
void GetSpouse(PERSON person, LP_PERSON spouse);C＃定义
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct PERSON
{
public int age;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
public string name;
}
[DllImport("family.dll", CharSet = CharSet.Auto)]
public static extern bool GetSpouse(PERSON person, ref PERSON spouse);具有未知大小数组字段的结构。传入
C++签名
typedef struct
{
int length;
int *data;
} VECTOR;
void SetVector(VECTOR &vector);从托管代码传递到非托管代码时，此
所述data阵列应该被定义为的IntPtr和存储器应该与显式地分配（和释放与后记）：Marshal.AllocHGlobal()Marshal.FreeHGlobal()
[StructLayout(LayoutKind.Sequential)]
public struct VECTOR : IDisposable
{
int length;
IntPtr dataBuf;
public int[] data
{
set
{
FreeDataBuf();
if (value != null &&value.Length> 0)
{
dataBuf = Marshal.AllocHGlobal(value.Length * Marshal.SizeOf(value[0]));
Marshal.Copy(value, 0, dataBuf, value.Length);
length = value.Length;
}
}
}
void FreeDataBuf()
{
if (dataBuf != IntPtr.Zero)
{
Marshal.FreeHGlobal(dataBuf);
dataBuf = IntPtr.Zero;
}
}
public void Dispose()
{
FreeDataBuf();
}
}
[DllImport("vectors.dll")]
public static extern void SetVector([In]ref VECTOR vector);具有未知大小数组字段的结构。接收
C++签名：
typedef struct
{
char *name;
} USER;
bool GetCurrentUser(USER *user);当此类数据从非托管代码中传递出去并由非托管函数分配内存时，托管调用者应将其接收到一个IntPrt变量中，并将缓冲区转换为托管数组。对于字符串，有一个方便的方法：Marshal.PtrToStringAnsi()
[StructLayout(LayoutKind.Sequential)]
public struct USER
{
IntPtr nameBuffer;
public string name { get { return Marshal.PtrToStringAnsi(nameBuffer); } }
}
[DllImport("users.dll")]
public static extern bool GetCurrentUser(out USER user);