我有一个未修饰的 JavaFX 舞台，以及我自己的最小化、最大化和关闭按钮。但不幸的是，与装饰行为相比，在 Windows 7 中单击任务栏图标不会自动最小化舞台。

有没有一种方法可以通过单击任务栏图标来使用纯 Java 代码最小化未修饰的阶段？如果不是，我如何使用 JNA 来做到这一点？

编辑: 好的，我一直在尝试用 JNA 解决这个问题，但是几乎没有完成任何 C/C++/JNA，我在设置它时遇到了一些麻烦。如果有人帮我把这些碎片拼在一起，我将不胜感激。

到目前为止，这是我的代码:

public final class Utils {

   static {
    if (PlatformUtil.isWin7OrLater()) {
            Native.register("shell32");
            Native.register("user32");
        }
    }

    // Apparently, this is the event I am after
    public static final int WM_ACTIVATEAPP = 0x1C;


    public static void registerMinimizeHandler(Stage stage) {
       // Hacky way to get a pointer to JavaFX Window
       Pointer pointer = getWindowPointer(stage);

       WinDef.HWND hwnd = new WinDef.HWND(pointer);

       // Here's my minimize/activate handler
       WinUser.WindowProc windowProc = new MinimizeHandler(stage);

       Pointer magicPointer = ... set this to point to windowProc?

       // This.. apparently, re-sets the WndProc? But how do I get the "magicPointer" that is "attached" to the windowProc?
       User32.INSTANCE.SetWindowLong(hwnd, User32.GWL_WNDPROC, magicPointer);
    }
}

 private static class MinimizeHandler implements WinUser.WindowProc {

    private Stage stage;

    private MinimizeHandler(Stage stage) {
        this.stage = stage;
    }

    @Override
    public WinDef.LRESULT callback(WinDef.HWND hWnd, int uMsg, WinDef.WPARAM wParam, WinDef.LPARAM lParam) {
        if (uMsg == WM_ACTIVATEAPP) {
            System.out.println("ACTIVATE");
        }
        return User32.INSTANCE.DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
}

private static Pointer getWindowPointer(Stage stage) {
    try {
        TKStage tkStage = stage.impl_getPeer();
        Method getPlatformWindow = tkStage.getClass().getDeclaredMethod("getPlatformWindow" );
        getPlatformWindow.setAccessible(true);
        Object platformWindow = getPlatformWindow.invoke(tkStage);
        Method getNativeHandle = platformWindow.getClass().getMethod( "getNativeHandle" );
        getNativeHandle.setAccessible(true);
        Object nativeHandle = getNativeHandle.invoke(platformWindow);
        return new Pointer((Long) nativeHandle);
    } catch (Throwable e) {
        System.err.println("Error getting Window Pointer");
        return null;
    }
}

编辑 2: 我最终在这方面取得了进一步的进展，但是一旦我重新设置 WNDPROC，我未装饰的窗口就没有响应任何事件。我提供了一个具有工作解决方案的独立示例悬赏 100 声望。仅 Windows (7+) 可以，我什至不知道它在其他平台上的表现如何。

编辑 3: 好吧，我有点放弃了。我已经正确设置了所有内容，并收到了事件，但在确定要监听的正确事件时遇到了问题。

既然有人对这个问题感兴趣，如果有人想尝试继续这个问题，这是我的最终代码(希望它应该开箱即用):

public final class Utils {

    static interface ExtUser32 extends StdCallLibrary, User32 {
        ExtUser32 INSTANCE = (ExtUser32) Native.loadLibrary(
                        "user32",
                        ExtUser32.class,
                        W32APIOptions.DEFAULT_OPTIONS);

        WinDef.LRESULT CallWindowProcW(
                        Pointer lpWndProc,
                        Pointer hWnd,
                        int msg,
                        WinDef.WPARAM wParam,
                        WinDef.LPARAM lParam);

        int SetWindowLong(HWND hWnd, int nIndex, com.sun.jna.Callback wndProc) throws LastErrorException;
    }

    // Some possible event types
    public static final int WM_ACTIVATE = 0x0006;
    public static final int WM_ACTIVATEAPP = 0x1C;
    public static final int WM_NCACTIVATE = 0x0086;

    public static void registerMinimizeHandler(Stage stage) {
        Pointer pointer = getWindowPointer(stage);
        WinDef.HWND hwnd = new WinDef.HWND(pointer);
        long old = ExtUser32.INSTANCE.GetWindowLong(hwnd, User32.GWL_WNDPROC);
        MinimizeHandler handler = new MinimizeHandler(stage, old);
        ExtUser32.INSTANCE.SetWindowLong(hwnd, User32.GWL_WNDPROC, handler);
    }

    private static Pointer getWindowPointer(Stage stage) {
    try {
        TKStage tkStage = stage.impl_getPeer();
        Method getPlatformWindow = tkStage.getClass().getDeclaredMethod("getPlatformWindow" );
        getPlatformWindow.setAccessible(true);
        Object platformWindow = getPlatformWindow.invoke(tkStage);
        Method getNativeHandle = platformWindow.getClass().getMethod( "getNativeHandle" );
        getNativeHandle.setAccessible(true);
        Object nativeHandle = getNativeHandle.invoke(platformWindow);
        return new Pointer((Long) nativeHandle);
    } catch (Throwable e) {
        System.err.println("Error getting Window Pointer");
        return null;
    }
}

    private static class MinimizeHandler implements WinUser.WindowProc, StdCallLibrary.StdCallCallback {

        private Pointer mPrevWndProc32;

        private Stage stage;

        private MinimizeHandler(Stage stage, long oldPtr) {
            this.stage = stage;

            mPrevWndProc32 = new Pointer(oldPtr);

            // Set up an event pump to deliver messages for JavaFX to handle
            Thread thread = new Thread() {
                @Override
                public void run() {
                    int result;
                    WinUser.MSG msg = new WinUser.MSG();
                    while ((result = User32.INSTANCE.GetMessage(msg, null, 0, 0)) != 0) {
                        if (result == -1) {
                            System.err.println("error in get message");
                            break;
                        }
                        else {
                            System.out.println("got message: " + result);
                            User32.INSTANCE.TranslateMessage(msg);
                            User32.INSTANCE.DispatchMessage(msg);
                        }
                    }
                }
            };
            thread.start();
        }

        @Override
        public WinDef.LRESULT callback(WinDef.HWND hWnd, int uMsg, WinDef.WPARAM wParam, WinDef.LPARAM lParam) {

            if (uMsg == WM_ACTIVATEAPP) {
                // Window deactivated (wParam == 0)... Here's where I got stuck and gave up,
                // this is probably not the best event to listen to.. the app
                // does indeed get iconified now by pressing the task-bar button, but it
                // instantly restores afterwards..
                if (wParam.intValue() == 0) {
                    stage.setIconified(true);
                }
                return new WinDef.LRESULT(0);
            }

            // Let JavaFX handle other events
            return ExtUser32.INSTANCE.CallWindowProcW(
                            mPrevWndProc32,
                            hWnd.getPointer(),
                            uMsg,
                            wParam,
                            lParam);
        }
    }
}

最佳答案

您可以设置合适的窗口样式。它在 XP 中工作，但在 windows 7 32 位中应该没问题。 我认为(但无法测试)如果你使用 64 位然后更改为 Ptr Windows 功能，即。 GetWindowLongPtr.

import com.sun.jna.Native;
import com.sun.jna.Pointer;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef.HWND;
import com.sun.jna.platform.win32.WinUser;
import static com.sun.jna.platform.win32.WinUser.GWL_STYLE;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TextArea;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class JNATest extends Application {
    public static void main(String[] args) { launch(args); }

    @Override
    public void start(Stage stage) {
        TextArea ta = new TextArea("output\n");
        VBox root = new VBox(5,ta);
        Scene scene = new Scene(root,800,200);
        stage.setTitle("Find this window");
        stage.setScene(scene);
        stage.show();
        //gets this window (stage)
        long lhwnd = com.sun.glass.ui.Window.getWindows().get(0).getNativeWindow();
        Pointer lpVoid = new Pointer(lhwnd);
        //gets the foreground (focused) window
        final User32 user32 = User32.INSTANCE;
        char[] windowText = new char[512];
        HWND hwnd = user32.GetForegroundWindow();
        //see what the title is
        user32.GetWindowText(hwnd, windowText, 512);
        //user32.GetWindowText(new HWND(lpVoid), windowText, 512);//to use the hwnd from stage
        String text=(Native.toString(windowText));
        //see if it's the same pointer
        ta.appendText("HWND java:" + lpVoid + " HWND user32:"+hwnd+" text:"+text+"\n");
        //change the window style if it's the right title
        if (text.equals(stage.getTitle())){
            //the style to change 
            int WS_DLGFRAME = 0x00400000;//s/b long I think
            //not the same constant here??
            ta.appendText("windows api:"+WS_DLGFRAME+" JNA: "+WinUser.SM_CXDLGFRAME);
            int oldStyle = user32.GetWindowLong(hwnd, GWL_STYLE);
            int newStyle = oldStyle & ~0x00400000; //bitwise not WS_DLGFRAME means remove the style
            newStyle = newStyle & ~0x00040000;//WS_THICKFRAME   
            user32.SetWindowLong(hwnd, GWL_STYLE, newStyle);
        }
    }

}

我的猜测是你将最后 3 行替换为

            long oldStyleLong = user32.GetWindowLongPtr(hwnd, GWL_STYLE).longValue();
            long newStyleLong = oldStyleLong & ~ 0x00400000l;
            user32.SetWindowLongPtr(hwnd, GWL_STYLE, new BaseTSD.LONG_PTR(newStyleLong));

64 位。我想我的 User32.dll 中没有这些函数，所以我无法对其进行测试。里面有很多无关代码，主要用于测试或者教学。确定要执行的操作后，请删除未使用的行。

附言。不要添加 newStyle = newStyle & ~0x00020000;//WS_MINIMIZEBOX。这是 JavaFX 不用于未修饰的样式标志之一。这就是最小化不可用的原因。也许如果您尝试将舞台设置为未修饰并添加(使用 |，而不是 &~)最小化框标志，您将得到相同的结果。有一些工具可以从任何窗口中查找所有样式标志。

下面是最简单的代码量，仅使用舞台的 HWND 更改未修饰的舞台。

    public void start(Stage stage) {
        Scene scene = new Scene(new Pane(new Label("Hello World")));
        stage.initStyle(StageStyle.UNDECORATED);
        stage.setTitle("Find this window");
        stage.setScene(scene);
        stage.show();
        long lhwnd = com.sun.glass.ui.Window.getWindows().get(0).getNativeWindow();
        Pointer lpVoid = new Pointer(lhwnd);
        HWND hwnd = new HWND(lpVoid);
        final User32 user32 = User32.INSTANCE;
        int oldStyle = user32.GetWindowLong(hwnd, GWL_STYLE);
        System.out.println(Integer.toBinaryString(oldStyle));
        int newStyle = oldStyle | 0x00020000;//WS_MINIMIZEBOX
        System.out.println(Integer.toBinaryString(newStyle));
        user32.SetWindowLong(hwnd, GWL_STYLE, newStyle);
    }

它打印出之前和之后的样式标志，以便您可以查看设置了哪些样式。

关于JavaFX 最小化未修饰阶段，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26972683/