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.

看来您现在必须使用 JNI 来执行此操作.您是否有执行此操作的 JNI 代码和示例 Java 代码?

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?

我需要它来调用 Win32 GetWindowLong 和 SetWindowLong API 调用，这可以通过 Jawin 库完成.

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，以便我可以传递对 JDialog 或 JFrame 的引用并获取窗口句柄.

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 可能是相关的.

推荐答案

以下代码可让您传递一个 Component 以获取其窗口句柄 (HWND).要确保组件具有相应的窗口句柄，请在组件上调用 isLightWeight() 并验证它是否等于 false.如果没有，请通过调用 Component.getParent() 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 源代码 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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