在Java Swing中，如何获得对窗口的Win32窗口句柄（hwnd）引用？ [英] In Java Swing how do you get a Win32 window handle (hwnd) reference to a window?

问题描述

在Java 1.4中，您可以使用（（SunToolkit）Toolkit.getDefaultToolkit（））。getNativeWindowHandleFromComponent（）但已删除。

In Java 1.4 you could use ((SunToolkit) Toolkit.getDefaultToolkit()).getNativeWindowHandleFromComponent() but that was removed.

看起来您必须使用JNI现在就这么做。你有JNI代码和示例Java代码吗？

It looks like you have to use JNI to do this now. Do you have the JNI code and sample Java code to do this?

我需要这个来调用Win32 GetWindowLong和SetWindowLong API调用，这可以通过Jawin库来完成。

I need this to call the Win32 GetWindowLong and SetWindowLong API calls, which can be done via the Jawin library.

我想要一些非常精确的东西，所以我可以传递对JDialog或JFrame的引用并获得窗口句柄。

I would like something very precise so I can pass a reference to the JDialog or JFrame and get the window handle.

使用JNI的Swing透明度可能相关。

推荐答案

以下代码允许您传递Component以获取它的窗口句柄（HWND）。要确保Component具有相应的窗口句柄，请在Component上调用isLightWeight（）并验证它是否等于false。如果没有，请通过调用Component.getParent（）来尝试它的父级。

The following code lets you pass a Component to get the window handle (HWND) for it. To make sure that a Component has a corresponding window handle call isLightWeight() on the Component and verify that it equals false. If it doesn't, try it's parent by calling Component.getParent().

Java代码：

package win32;
public class Win32 {
    public static native int getWindowHandle(Component c);
}

头文件main.h：

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class win32_Win32 */

#ifndef _Included_win32_Win32
#define _Included_win32_Win32
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     win32_Win32
 * Method:    getWindowHandle
 * Signature: (Ljava/awt/Component;Ljava/lang/String;)I
 */
JNIEXPORT jint JNICALL Java_win32_Win32_getWindowHandle
  (JNIEnv *, jclass, jobject);
#ifdef __cplusplus
}
#endif
#endif

C source main.c：

The C source main.c:

#include<windows.h>
#include <jni.h>
#include <jawt.h>
#include <jawt_md.h>

HMODULE _hAWT = 0;

JNIEXPORT jint JNICALL Java_win32_Win32_getWindowHandle
  (JNIEnv * env, jclass cls, jobject comp)
{
    HWND hWnd = 0;
    typedef jboolean (JNICALL *PJAWT_GETAWT)(JNIEnv*, JAWT*);
    JAWT awt;
    JAWT_DrawingSurface* ds;
    JAWT_DrawingSurfaceInfo* dsi;
    JAWT_Win32DrawingSurfaceInfo* dsi_win;
    jboolean result;
    jint lock;

    //Load AWT Library
    if(!_hAWT)
        //for Java 1.4
        _hAWT = LoadLibrary("jawt.dll");
    if(!_hAWT)
        //for Java 1.3
        _hAWT = LoadLibrary("awt.dll");
    if(_hAWT)
    {
        PJAWT_GETAWT JAWT_GetAWT = (PJAWT_GETAWT)GetProcAddress(_hAWT, "_JAWT_GetAWT@8");
        if(JAWT_GetAWT)
        {
            awt.version = JAWT_VERSION_1_4; // Init here with JAWT_VERSION_1_3 or JAWT_VERSION_1_4
            //Get AWT API Interface
            result = JAWT_GetAWT(env, &awt);
            if(result != JNI_FALSE)
            {
                ds = awt.GetDrawingSurface(env, comp);
                if(ds != NULL)
                {
                    lock = ds->Lock(ds);
                    if((lock & JAWT_LOCK_ERROR) == 0)
                    {
                        dsi = ds->GetDrawingSurfaceInfo(ds);
                        if(dsi)
                        {
                            dsi_win = (JAWT_Win32DrawingSurfaceInfo*)dsi->platformInfo;
                            if(dsi_win)
                            {
                                hWnd = dsi_win->hwnd;
                            }
                            else {
                                hWnd = (HWND) -1;
                            }
                            ds->FreeDrawingSurfaceInfo(dsi);
                        }
                        else {
                            hWnd = (HWND) -2;
                        }
                        ds->Unlock(ds);
                    }
                    else {
                        hWnd = (HWND) -3;
                    }
                    awt.FreeDrawingSurface(ds);
                }
                else {
                    hWnd = (HWND) -4;
                }
            }
            else {
                hWnd = (HWND) -5;
            }
        }
        else {
            hWnd = (HWND) -6;
        }
    }
    else {
        hWnd = (HWND) -7;
    }
    return (jint)hWnd;

}

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