Now I figured out this it's not data type (unsigned short) issue I thought, it's actually a nested ally of structure trouble

Before I simplified my data structure, really it is

typedef struct { char* a; StructA sa; StructB* sb; double c; double d; } Info;

typedef struct { short x; short y; short z; StructC w[16] } StructA;

typedef struct { short sh; double do } StructC;

I searched mail list archive found many talks about such issue, but couldn't find a clear solution, my java code as below

public static class Info extends Structure{ public String a; public StructA sa; public Pointer sb; public double c; public double d; }

public static class StructA extends Structure{ public short x; public short y; public short w; public StructC sc = new StructC[16];

public StructA(){ allocateMemory(); } }

public static class StructC extends Structure{ public short sh; public double do; }

I always got "invalid memory access" error, however, if I 1. comment out one of element from StructC ( short sh OR double do), it runs fine. 2. if I don't have array, just one of StructC in StructA, it's OK.

So seems it can't allocate enough memory for an array of StructC.

Moreover, I tried to change the "double" in StructC to "int", it runs OK, just I can't get the result I want.

I'm sure must be someone had this issue before, and helps please

Hao

Hao