我有一个非常大的应用程序，有多个对话框。我的任务是确保不完全可见的对话框（因为用户将其拉出可见屏幕区域）移回屏幕中心。
当我只处理一个屏幕时，这没问题。
它工作得很好......但是，这个应用程序的大多数用户的桌面上有两个屏幕......
当我尝试找出对话框显示在哪个屏幕上并将其居中在该特定屏幕上时，...好吧，它实际上确实居中，但在主屏幕上（可能不是显示对话框的屏幕）开）。
为了向您展示到目前为止我的想法，这是代码......
/**
* Get the number of the screen the dialog is shown on ...
*/
private static int getActiveScreen(JDialog jd) {
int screenId = 1;
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice[] gd = ge.getScreenDevices();
for (int i = 0; i < gd.length; i++) {
GraphicsConfiguration gc = gd[i].getDefaultConfiguration();
Rectangle r = gc.getBounds();
if (r.contains(jd.getLocation())) {
screenId = i + 1;
}
}
return screenId;
}
/**
* Get the Dimension of the screen with the given id ...
*/
private static Dimension getScreenDimension(int screenId) {
Dimension d = new Dimension(0, 0);
if (screenId > 0) {
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
DisplayMode mode = ge.getScreenDevices()[screenId - 1].getDisplayMode();
d.setSize(mode.getWidth(), mode.getHeight());
}
return d;
}
/**
* Check, if Dialog can be displayed completely ...
* @return true, if dialog can be displayed completely
*/
private boolean pruefeDialogImSichtbarenBereich() {
int screenId = getActiveScreen(this);
Dimension dimOfScreen = getScreenDimension(screenId);
int xPos = this.getX();
int yPos = this.getY();
Dimension dimOfDialog = this.getSize();
if (xPos + dimOfDialog.getWidth() > dimOfScreen.getWidth() || yPos + dimOfDialog.getHeight() > dimOfScreen.getHeight()) {
return false;
}
return true;
}
/**
* Center Dialog...
*/
private void zentriereDialogAufMonitor() {
this.setLocationRelativeTo(null);
}
在调试时，我发现
getActiveScreen()有人知道如何将我的对话框置于屏幕中央吗？它实际上是显示在屏幕上的？
您的
getActiveScreensetLocationRelativeTo(null)static boolean windowFitsOnScreen(Window w) {
return w.getGraphicsConfiguration().getBounds().contains(w.getBounds());
}
static void centerWindowToScreen(Window w) {
Rectangle screen = w.getGraphicsConfiguration().getBounds();
w.setLocation(
screen.x + (screen.width - w.getWidth()) / 2,
screen.y + (screen.height - w.getHeight()) / 2
);
}
然后你可以这样做：
JDialog jd;
...
if (!windowFitsOnScreen(jd)) centerWindowToScreen(jd);
这将使对话框居中到最近的屏幕（显示器）。您可能需要确保对话框最初已显示/定位。
我不确定其中有多少用处，但这是我在尝试确定 Windows 图形设备时使用的代码。
我有点作弊，我倾向于使用
ComponentComponent/**
* Returns the GraphicsDevice that the specified component appears the most on.
*/
public static GraphicsDevice getGraphicsDevice(Component comp) {
GraphicsDevice device = null;
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice lstGDs[] = ge.getScreenDevices();
ArrayList<GraphicsDevice> lstDevices = new ArrayList<GraphicsDevice>(lstGDs.length);
if (comp != null && comp.isVisible()) {
Rectangle parentBounds = comp.getBounds();
/*
* If the component is not a window, we need to find its location on the
* screen...
*/
if (!(comp instanceof Window)) {
Point p = new Point(0, 0);
SwingUtilities.convertPointToScreen(p, comp);
parentBounds.setLocation(p);
}
for (GraphicsDevice gd : lstGDs) {
GraphicsConfiguration gc = gd.getDefaultConfiguration();
Rectangle screenBounds = gc.getBounds();
if (screenBounds.intersects(parentBounds)) {
lstDevices.add(gd);
}
}
if (lstDevices.size() == 1) {
device = lstDevices.get(0);
} else {
GraphicsDevice gdMost = null;
float maxArea = 0;
for (GraphicsDevice gd : lstDevices) {
int width = 0;
int height = 0;
GraphicsConfiguration gc = gd.getDefaultConfiguration();
Rectangle bounds = gc.getBounds();
Rectangle2D intBounds = bounds.createIntersection(parentBounds);
float perArea = (float) ((intBounds.getWidth() * intBounds.getHeight()) / (parentBounds.width * parentBounds.height));
if (perArea > maxArea) {
maxArea = perArea;
gdMost = gd;
}
}
if (gdMost != null) {
device = gdMost;
}
}
}
return device;
}
/**
* Returns the GraphicsDevice at the specified point
*/
public static GraphicsDevice getGraphicsDeviceAt(Point pos) {
GraphicsDevice device = null;
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice lstGDs[] = ge.getScreenDevices();
List<GraphicsDevice> lstDevices = new ArrayList<GraphicsDevice>(lstGDs.length);
for (GraphicsDevice gd : lstGDs) {
GraphicsConfiguration gc = gd.getDefaultConfiguration();
Rectangle screenBounds = gc.getBounds();
if (screenBounds.contains(pos)) {
lstDevices.add(gd);
}
}
if (lstDevices.size() > 0) {
device = lstDevices.get(0);
}
return device;
}
/**
* Returns the Point that would allow the supplied Window to be
* centered on it's current graphics device.
*
* It's VERY important that the Window be seeded with a location
* before calling this method, otherwise it will appear on the
* device at 0x0
*
* @param window
* @return
*/
public static Point centerOfScreen(Window window) {
// Try and figure out which window we actually reside on...
GraphicsDevice gd = getGraphicsDeviceAt(window.getLocation());
GraphicsConfiguration gc = gd.getDefaultConfiguration();
Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets(gd.getDefaultConfiguration());
Rectangle bounds = gc.getBounds();
Dimension size = bounds.getSize();
size.width -= (screenInsets.left + screenInsets.right);
size.height -= (screenInsets.top + screenInsets.bottom);
int width = window.getWidth();
int height = window.getHeight();
int xPos = screenInsets.left + ((size.width - width) / 2);
int yPos = screenInsets.top + ((size.height - height) / 2);
return new Point(xPos, yPos);
}
这是用于使窗口居中位置的代码。
//Center the window
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Dimension frameSize = frame.getSize();
if (frameSize.height > screenSize.height) {
frameSize.height = screenSize.height;
}
if (frameSize.width > screenSize.width) {
frameSize.width = screenSize.width;
}
frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
通过
frame