JNA以结构体数组为参数进行调用:
- ////// C++
- // student 结构体定义
- typedef struct
- {
- int age;
- char name[20];
- }Student;
- // 修改java对象的属性值
- JNAAPI bool changeObjs(Student stu[],int size)
- {
- for(int i=0;i<size;i++)
- {
- stu[i].age*=10;
- strcpy(stu[i].name,"wokettas");
- }
- return true;
- }
- /////// Java
- // JNA调用方法
- Student[] stus=new Students[2];
- Student s1=new Student();
- Student s2=new Student();
- s1.age=1;
- s1.name=Arrays.copyOf("k1".getBytes(), 20);
- s2.age=2;
- s2.name=Arrays.copyOf("k2".getBytes(),20);
- stus[0]=s1; //数组赋值
- stus[1]=s2;
- Gui.gui.changeObjs(stus, stus.length);
运行报错:
Structure array elements must use contiguous memory (bad backing address at Structure array index 1)
结构体数组必须使用连续的内存区域, 上例s1,s2都是new出来的新对象,不可能连续; 也就是说传统方式的初始化数组不能解决, 查询JNA api发现里面提供了:
toArray
public Structure[] toArray(int size)
Returns a view of this structure's memory as an array of structures. Note that this Structure must have a public, no-arg constructor. If the structure is currently using a Memory backing, the memory will be resized to fit the entire array.
修改后的代码:
- // 测试对象数组
- Student student=new Student();
- Student[] stus=(Student[]) student.toArray(2); //分配大小为2的结构体数组
- stus[0].age=1;
- stus[0].name=Arrays.copyOf("k1".getBytes(), 20);
- stus[1].age=2;
- stus[1].name=Arrays.copyOf("k2".getBytes(),20);
- Gui.gui.changeObjs(stus, stus.length);
http://tcspecial.iteye.com/blog/1665583 //原文地址