Thanks to Timothy for solving my initial problems. I now run into another problem where I get an exception using nested Structures:

interface Test extends Library {

class MyNumberPart extends Structure { public int part; }

class MyNumber extends Structure { public int num; public MyNumberPart[] parts;

public MyNumber() { parts = (MyNumberPart[])new MyNumberPart().toArray(2); } }

int calculateSum(MyNumber[] numbers, int arraySize); }

My test method:

public void TestMethod() {

MyNumber[] numbers = (MyNumber[])new MyNumber().toArray(2); numbers[0].num = 4; numbers[0].parts[0].part = 1; numbers[0].parts[1].part = 2;

numbers[1].num = 3; numbers[1].parts[0].part = 3; numbers[1].parts[1].part = 4;

int sum = Test.calculateSum(numbers); }

Then I get this exception:

java.lang.IndexOutOfBoundsException: Bounds exceeds available space : size=12, offset=24 at com.sun.jna.Memory.boundsCheck(Memory.java:149) at com.sun.jna.Memory.share(Memory.java:90) at com.sun.jna.Structure.toArray(Structure.java:977) at com.sun.jna.Structure.toArray(Structure.java:989)

Again, thanks for your help!

regards, Niels.