JNA struct Array

This article describes how to simulate a struct using JNA and pass the struct array as a parameter to the corresponding method.

The C language struct is defined as follows:

typedef struct Rect{int top;int bottom;int left;int right;} RECT;

JNA simulates the struct:

Need to introduce:

Import com. Sun. JNA .*;
Import com. Sun. JNA. PTR .*;

// The Order of the public fields in the public static class rect extends Structure {// structure subclass must be the same as that in the C language; otherwise, an error is reported! Public int top; Public int bottom; Public int left; Public int right; public static class byreference extends rect implements structure. byreference {} public static class byvalue extends rect implements structure. byvalue {}@ override protected list getfieldorder () {return arrays. aslist (New String [] {"TOP", "bottom", "Left", "right "});}}

How can I transfer a struct array object to a method?

C language functions:

// Rects: struct array, Len: array length void function (rect * rects, int Len );

JNA simulation is as follows:

void function(Rect[] rects,int len);

The call method is as follows:

Int Len = 5; // define the array rect [] array = (rect []) New rect (). toarray (LEN); function (array, Len );

In fact, this mainly refers to the creation of struct arrays. Note: if the following method is used to create a struct array, an empty array will be generated and the requested space will not be available, currently, I do not know why I cannot apply for space.

int len = 5;Rect[] array = new Rect[len];

After this code is executed, array = NULL, that is, an error occurred while creating the array!

Hope experts can help answer this question!