Java JNR-FFI如何从一个指针到另一个指针读取结构数组

我正在尝试使用与C库接口

有一个函数：

public static class zbc_zone extends Struct 
{
    protected zbc_zone(Runtime runtime) {
        super(runtime);
    }
    public final Unsigned64 zbz_length=new Unsigned64();
    public final Unsigned64 zbz_start=new Unsigned64();
    public final Unsigned64 zbz_write_pointer=new Unsigned64();
    public final Unsigned8 zbz_type=new Unsigned8();
    public final Unsigned8 zbz_conditions=new Unsigned8();
    public final Unsigned8 zbz_attributes=new Unsigned8();
    public final Unsigned8 zbz_pad1=new Unsigned8();
    public final Unsigned8 zbz_pad2=new Unsigned8();
    public final Unsigned8 zbz_pad3=new Unsigned8();
    public final Unsigned8 zbz_pad4=new Unsigned8();
    public final Unsigned8 zbz_pad5=new Unsigned8();
}

public int zbc_list_zones(@In Pointer dev,@In long sector,
    @In zbc_reporting_options options,@Out PointerByReference zones,
    @Out IntByReference nr_zones);

int zbc_列表_区域（结构zbc_设备*开发，uint64_t扇区，枚举 zbc_报告选项ro，结构zbc_区域**区域，无符号整数* nr_区）

如何从参数区域读回结构数组

第二个问题：nr_zones参数声明是否正确？结果整数为负，应为正。我尝试使用ShortByReference，给出了一个合理的结果，但我认为这不正确

我尝试了以下方法来读取第一个元素，但它不起作用（结果为零）：

zbc_区域结构：

public static class zbc_zone extends Struct 
{
    protected zbc_zone(Runtime runtime) {
        super(runtime);
    }
    public final Unsigned64 zbz_length=new Unsigned64();
    public final Unsigned64 zbz_start=new Unsigned64();
    public final Unsigned64 zbz_write_pointer=new Unsigned64();
    public final Unsigned8 zbz_type=new Unsigned8();
    public final Unsigned8 zbz_conditions=new Unsigned8();
    public final Unsigned8 zbz_attributes=new Unsigned8();
    public final Unsigned8 zbz_pad1=new Unsigned8();
    public final Unsigned8 zbz_pad2=new Unsigned8();
    public final Unsigned8 zbz_pad3=new Unsigned8();
    public final Unsigned8 zbz_pad4=new Unsigned8();
    public final Unsigned8 zbz_pad5=new Unsigned8();
}

public int zbc_list_zones(@In Pointer dev,@In long sector,
    @In zbc_reporting_options options,@Out PointerByReference zones,
    @Out IntByReference nr_zones);

JNR接口：

public static class zbc_zone extends Struct 
{
    protected zbc_zone(Runtime runtime) {
        super(runtime);
    }
    public final Unsigned64 zbz_length=new Unsigned64();
    public final Unsigned64 zbz_start=new Unsigned64();
    public final Unsigned64 zbz_write_pointer=new Unsigned64();
    public final Unsigned8 zbz_type=new Unsigned8();
    public final Unsigned8 zbz_conditions=new Unsigned8();
    public final Unsigned8 zbz_attributes=new Unsigned8();
    public final Unsigned8 zbz_pad1=new Unsigned8();
    public final Unsigned8 zbz_pad2=new Unsigned8();
    public final Unsigned8 zbz_pad3=new Unsigned8();
    public final Unsigned8 zbz_pad4=new Unsigned8();
    public final Unsigned8 zbz_pad5=new Unsigned8();
}

public int zbc_list_zones(@In Pointer dev,@In long sector,
    @In zbc_reporting_options options,@Out PointerByReference zones,
    @Out IntByReference nr_zones);

---

有三种方法可以帮助您：

指针#切片-将返回按偏移量移动的新指针

Struct#size-返回结构的大小（以字节为单位）

结构#使用内存-将内存映射到结构字段

所以，您应该创建一个结构，记住它的大小，对于原始指针中的每个i in n片i*大小，并在创建的结构中使用新指针的内存