我有基于C / C ++结构的JNA结构的问题。字段nScreenIndex,uVendorID,uProductID,uVersionNumber看起来没问题,但在它们之后我看到奇数字节。我的主要目的是“提取”pMonitor字段。 pMonitor 声明和 MONITOR 实施是否正确?
C / C ++起源:
SCREEN* EloGetScreenByIndex (int nScreenIndex);
typedef struct SCREEN_TAG
{
int nScreenIndex;
USHORT uVendorID;
USHORT uProductID;
USHORT uVersionNumber;
wchar_t szDevicePath [MAX_PATH];
HANDLE hCalTouchThread;
MONITOR* pMonitor;
LPVOID pCWndBeamHandler;
BOOL bIrBeams;
} SCREEN;
typedef struct MONITORS_TAG
{
int elo_mon_num;
int x;
int y;
int width;
int height;
DWORD orientation;
bool is_primary;
} MONITOR;
和Java / JNA代码:
SCREEN EloGetScreenByIndex(int nScreenIndex);
public class SCREEN extends Structure {
public int nScreenIndex;
public short uVendorID;
public short uProductID;
public short uVersionNumber;
public char[] szDevicePath = new char[WinDef.MAX_PATH];
public WinNT.HANDLE hCalTouchThread;
public MONITOR pMonitor;
public PointerByReference pCWndBeamHandler;
public boolean bIrBeams;
...
}
public class MONITOR extends Structure {
public int elo_mon_num;
public int x;
public int y;
public int width;
public int height;
public int orientation;
public byte is_primary;
public MONITOR() {
super();
}
@Override
protected List<? > getFieldOrder() {
return Arrays.asList("elo_mon_num", "x", "y", "width", "height", "orientation", "is_primary");
}
public MONITOR(Pointer peer) {
super(peer);
}
public static class ByReference extends MONITOR implements Structure.ByReference {
};
public static class ByValue extends MONITOR implements Structure.ByValue {
};
}
答案 0 :(得分:2)
你非常接近正确。
在java的SCREEN类中,您需要将pMonitor
定义为:
public MONITOR.ByReference pMonitor;
这是per the FAQ。
我什么时候应该使用Structure.ByReference? Structure.ByValue?结构体[]?
typedef struct _outerstruct2 {
simplestruct *byref; // use Structure.ByReference
} outerstruct2;
作为附录:
当我使用mingw编译
dll
来解决这个问题时,我必须继承StdCallLibrary
而不是Library
- 这可能不是你的情况,我是只是提到这个因为它影响了我的测试。