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

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：函数GetWindowPlacement的参数1处的不支持的参数类型jna.extra.WINDOWPLACEMENT

如何在JNA中使用GetWindowPlacement / SetWindowPlacement？

Answer 1

java.extra.WINDOWPLACEMENT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"); } // ... }