java - 为什么我对 winapi GetWindowPlacement 的调用失败(使用 JNA)？

Question

这些是 winapi 方法

BOOL WINAPI SetWindowPlacement(
  _In_       HWND            hWnd,
  _In_ const WINDOWPLACEMENT *lpwndpl
);
typedef struct tagWINDOWPLACEMENT {
  UINT  length;
  UINT  flags;
  UINT  showCmd;
  POINT ptMinPosition;
  POINT ptMaxPosition;
  RECT  rcNormalPosition;
} WINDOWPLACEMENT, *PWINDOWPLACEMENT, *LPWINDOWPLACEMENT;

我的Java代码:-

class WINDOWPLACEMENT{
   public int length;
   public int flags;
   public int showCmd;
   public POINT    ptMinPosition;
   public POINT    ptMaxPosition;
   public RECT     rcNormalPosition;
}
WINDOWPLACEMENT wind = new WINDOWPLACEMENT();
User32Extra.INSTANCE.GetWindowPlacement(hwndLSM, wind);

错误是

java.lang.IllegalArgumentException: Unsupported argument type jna.extra.WINDOWPLACEMENT at parameter 1 of function GetWindowPlacement

如何通过 JNA 使用 GetWindowPlacement/SetWindowPlacement？

Answer 1

java.extra.WINDOWPLACMENT 必须扩展 com.sun.jna.Structure 并正确实现 getFieldOrder()。

编辑

在构造函数中设置长度，以及getFieldOrder()定义:

public class WINDOWPLACEMENT extends Structure {
    public WINDOWPLACEMENT() {
        this.length = size();
    }
    public List getFieldOrder() {
        return Arrays.asList("length", "flags", "showCmd", "ptMinPosition", "ptMaxPosition", "rcNormalPosition");
    }
    // ...
}