如何在Java中居中窗口？

Question

什么是最简单的中心方式java.awt.Window,例如a JFrame或a JDialog？

Answer 1

从这个链接

如果您使用的是Java 1.4或更高版本,则可以在对话框,框架或窗口上使用简单方法setLocationRelativeTo(null)来使其居中.

Answer 2

这应该适用于所有版本的Java

public static void centreWindow(Window frame) {
    Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
    int x = (int) ((dimension.getWidth() - frame.getWidth()) / 2);
    int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
    frame.setLocation(x, y);
}

Answer 3

请注意,setLocationRelativeTo(null)和Tookit.getDefaultToolkit().getScreenSize()技术仅适用于主监视器.如果您处于多监视器环境中,则可能需要在执行此类计算之前获取有关窗口所在的特定监视器的信息.

有时重要,有时不...

有关如何获取此信息的详细信息,请参阅GraphicsEnvironment javadocs.

Answer 4

在使用setSize(x,y)或使用pack()之后应该调用setLocationRelativeTo(null).

Answer 5

在Linux上的代码

    setLocationRelativeTo(null)

每次我启动它时,在多显示环境中将窗口置于随机位置.和代码

    setLocation((Toolkit.getDefaultToolkit().getScreenSize().width  - getSize().width) / 2, (Toolkit.getDefaultToolkit().getScreenSize().height - getSize().height) / 2);

将窗口"切"成两半,将其放置在我的两个显示器之间的确切中心.我使用以下方法来集中它:

private void setWindowPosition(JFrame window, int screen)
{        
    GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
    GraphicsDevice[] allDevices = env.getScreenDevices();
    int topLeftX, topLeftY, screenX, screenY, windowPosX, windowPosY;

    if (screen < allDevices.length && screen > -1)
    {
        topLeftX = allDevices[screen].getDefaultConfiguration().getBounds().x;
        topLeftY = allDevices[screen].getDefaultConfiguration().getBounds().y;

        screenX  = allDevices[screen].getDefaultConfiguration().getBounds().width;
        screenY  = allDevices[screen].getDefaultConfiguration().getBounds().height;
    }
    else
    {
        topLeftX = allDevices[0].getDefaultConfiguration().getBounds().x;
        topLeftY = allDevices[0].getDefaultConfiguration().getBounds().y;

        screenX  = allDevices[0].getDefaultConfiguration().getBounds().width;
        screenY  = allDevices[0].getDefaultConfiguration().getBounds().height;
    }

    windowPosX = ((screenX - window.getWidth())  / 2) + topLeftX;
    windowPosY = ((screenY - window.getHeight()) / 2) + topLeftY;

    window.setLocation(windowPosX, windowPosY);
}

使窗口显示在第一个显示屏的中央.这可能不是最简单的解决方案.

适用于Linux,Windows和Mac.

Answer 6

我终于使用 Swing GUI Forms 使这堆代码在 NetBeans 中工作，以便将主 jFrame 居中：

package my.SampleUIdemo;
import java.awt.*;

public class classSampleUIdemo extends javax.swing.JFrame {
    /// 
    public classSampleUIdemo() {
        initComponents();
        CenteredFrame(this);  // <--- Here ya go.
    }
    // ...
    // void main() and other public method declarations here...

    ///  modular approach
    public void CenteredFrame(javax.swing.JFrame objFrame){
        Dimension objDimension = Toolkit.getDefaultToolkit().getScreenSize();
        int iCoordX = (objDimension.width - objFrame.getWidth()) / 2;
        int iCoordY = (objDimension.height - objFrame.getHeight()) / 2;
        objFrame.setLocation(iCoordX, iCoordY); 
    } 

}

或者

package my.SampleUIdemo;
import java.awt.*;

public class classSampleUIdemo extends javax.swing.JFrame {
        /// 
        public classSampleUIdemo() {
            initComponents(); 
            //------>> Insert your code here to center main jFrame.
            Dimension objDimension = Toolkit.getDefaultToolkit().getScreenSize();
            int iCoordX = (objDimension.width - this.getWidth()) / 2;
            int iCoordY = (objDimension.height - this.getHeight()) / 2;
            this.setLocation(iCoordX, iCoordY); 
            //------>> 
        } 
        // ...
        // void main() and other public method declarations here...

}

或者

    package my.SampleUIdemo;
    import java.awt.*;
    public class classSampleUIdemo extends javax.swing.JFrame {
         /// 
         public classSampleUIdemo() {
             initComponents();
             this.setLocationRelativeTo(null);  // <<--- plain and simple
         }
         // ...
         // void main() and other public method declarations here...
   }