我正在尝试使用来自 VS2012 C# env 的本机 dll。我有一个奇怪的场景：case1：
IntPtr p_stat = IntPtr.Zero;
dcUe.dcUeGetMacStats(_helper.Handle, out p_stat);//native function call thatallocates memory and points the pointer to it
MacStatistics stats = (MacStatistics)Marshal.PtrToStructure(p_stat, typeof(MacStatistics));
使用以下 Pinvoke 包装器：
[DllImport("dcc.dll",CharSet=CharSet.Ansi, CallingConvention = CallingConvention.Cdecl)]
public static extern UInt32 dcUeGetMacStats(thpHandle_t handle, /* MacStatistics*/out IntPtr stats);
这是课程：
[StructLayout(LayoutKind.Sequential)]
public class MacStatistics {
public u32 activeDemultFailNumber;
public u32 activeDemultySuccessNumber;
public u32 pdschTotalDataNumber;
public u16 taTimerLength;
public u32 activePdschCrcCorrectNumber;
public u32 activePdschCrcErrorNumber;
public u8 antennaPortNumber;
public u32 dlSystemRbNumber;
public u32 parseDci0SuccessNumber;
public u32 pdschCrcCorrectNumber;
public u32 pdschCrcErrorNumber;
public u32 pdschDynamicNumber;
public u32 pdschSemiStaticNumber;
public u32 receiveDci0Number;
public u32 sendPucchSuccessNumber;
public u32 sendPuschSuccessNumber;
public u32 ulSubCarrierRBNumber;
public u32 ulSymbolNumber;
public u32 ulSystemRbNumber;
};
这种情况下工作正常情况2：
IntPtr p_stats = IntPtr.Zero;
st = dcUe.dcUeGetNasInfo(_helper.Handle, out p_stats);//nativs function call that allocates memory and points the pointer to it
NasInfo ueNasState = (NasInfo)Marshal.PtrToStructure(p_stats, typeof(NasInfo));
使用以下 Pinvoke 包装器：
[DllImport("dcc.dll",CharSet=CharSet.Ansi, CallingConvention = CallingConvention.Cdecl)]
public static extern UInt32 dcUeGetNasInfo(thpHandle_t handle, /* NasInfo*/out IntPtr info);
这是课程：
[StructLayout(LayoutKind.Sequential)]
public class NasInfo {
public EmmPlmnSelectMode plmnSelectMode;//enum
public u32 pdnQty;
public EpsPdnAddress pdnArray;
public Bool_t emmRegistred;
public Bool_t rrcConnected;
public EpsIntegrityAlgorithm integrityAlgo;//enum
public EpsCipheringAlgorithm cipheringAlgo;//enum
};
[StructLayout(LayoutKind.Sequential)]
public class EpsPdnAddress {
sqnBool_t epsIpv4AddressPresent;
u8 [] epsIpv4Address = new u8[4];
sqnBool_t epsIpv6AddressPresent;
u8 [] epsIpv6Address = new u8[8];
}
这种情况下会在以下行中引发 AccessViolationException：
NasInfo ueNasState = (NasInfo)Marshal.PtrToStructure(p_stats, typeof(NasInfo));
我真的很困惑，本机函数确实改变了 ptr 值，所以它似乎做了分配，但编组失败。
请帮忙谢谢mosh。
[更新已解决]
public class NasInfo {
public EmmPlmnSelectMode plmnSelectMode;//enum
public u32 pdnQty;
public EpsPdnAddress pdnArray;
public Bool_t emmRegistred;
public Bool_t rrcConnected;
public EpsIntegrityAlgorithm integrityAlgo;//enum
public EpsCipheringAlgorithm cipheringAlgo;//enum
};
改为
public class NasInfo {
public EmmPlmnSelectMode plmnSelectMode;//enum
public u32 pdnQty;
public /*EpsPdnAddress*/ IntPtr pdnArray;
public Bool_t emmRegistred;
public Bool_t rrcConnected;
public EpsIntegrityAlgorithm integrityAlgo;//enum
public EpsCipheringAlgorithm cipheringAlgo;//enum
};
和编组工作，但我失去了类型安全，有没有办法包装 IntPtr 并且仍然有一些关于原始结构/类的细节（在这种情况下为 EpsPdnAddress）