Java 使 JPanel 手动调整大小

Making a JPanel manually resizable

提问by saralk

I have a JFramewith BorderLayoutas the layout manager.

我有一个JFramewithBorderLayout作为布局管理器。

In the south border, I have a JPanel, I want this JPanel's size to be adjustable by the user, i.e. the user can click on the edge of the border and drag it up to make it larger.

在南边界，我有一个JPanel，我希望它JPanel的大小可以由用户调整，即用户可以单击边界的边缘并将其向上拖动以使其变大。

Is there any way you know that I can do this?

你有什么办法知道我可以做到这一点吗？

采纳答案by jjnguy

In order to make panels in a frame individually resizable you need to add them onto a JSplitPane.

为了使框架中的面板单独调整大小，您需要将它们添加到JSplitPane.

Instead of putting it in the South portion of the Frame, put the JSplitPanein the Center. The split pane will make the bottom panel in the split seem like it is in the South, and the top panel in the split will be in the Center of the frame.

不要把它放在框架的南部，而是把它放在JSplitPane中心。拆分窗格将使拆分中的底部面板看起来像是在南方，而拆分中的顶部面板将位于框架的中心。

Make sure you set the orientation of the two panels with setOrientation(JSplitPane.VERTICAL_SPLIT ).

确保使用 设置两个面板的方向setOrientation(JSplitPane.VERTICAL_SPLIT )。

Then, you can resize the panels that are in the pane.

然后，您可以调整窗格中面板的大小。

回答by Savvas Dalkitsis

I think you meant to say JPanel. You can add a custom mouseListener and handle mouse clicks, drags and mouse releases and then resize the panel programmaticaly.

我想你的意思是说JPanel。您可以添加自定义 mouseListener 并处理鼠标单击、拖动和鼠标释放，然后以编程方式调整面板大小。

This will demonstrate this. Note that the jframe does NOT resize automatically with the JPanel. To make the effect more visible i painted the panel red and added a beveled border :

这将证明这一点。请注意，jframe 不会随 JPanel 自动调整大小。为了使效果更明显，我将面板涂成红色并添加了一个斜角边框：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.BevelBorder;

@SuppressWarnings("serial")
public class ResizablePanel extends JPanel {

    private boolean drag = false;
    private Point dragLocation  = new Point();

    public  ResizablePanel() {
        setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));
        setPreferredSize(new Dimension(500, 500));
        final JFrame f = new JFrame("Test");
        addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                drag = true;
                dragLocation = e.getPoint();
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                drag = false;
            }
        });
        addMouseMotionListener(new MouseMotionAdapter() {
            @Override
            public void mouseDragged(MouseEvent e) {
                if (drag) {
                    if (dragLocation.getX()> getWidth()-10 && dragLocation.getY()>getHeight()-10) {
                        System.err.println("in");
                        setSize((int)(getWidth()+(e.getPoint().getX()-dragLocation.getX())),
                                (int)(getHeight()+(e.getPoint().getY()-dragLocation.getY())));
                        dragLocation = e.getPoint();
                    }
                }
            }
        });
        f.getContentPane().setLayout(new BorderLayout());
        f.getContentPane().add(this,BorderLayout.CENTER);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.pack();
        f.setVisible(true);
    }

    public static void main(String[] args) {
        new ResizablePanel();
    }

    public void paintComponent(Graphics g) {
        g.setColor(Color.red);
        g.fillRect(0, 0, getWidth(), getHeight());
    }

}

回答by Savvas Dalkitsis

You might have to specify JFrame.setResizeable = true;on both the Parent JFrame(the one with the border layout) and the child JFrame.

您可能必须同时指定JFrame.setResizeable = true;Parent JFrame（带有边框布局的那个）和 child JFrame。

You also might want to use a JPanelin the south border.

您可能还想JPanel在南部边界使用 a 。

回答by Bode

I made a class for that if you want to take a look. It isn`t finished yet.

如果你想看一看，我为此做了一门课。还没完呢。

package projetoSplitPainel;

import java.awt.Component;
import java.util.ArrayList;

import javax.swing.JSplitPane;

/**
 * This Components is based on the JSplitPane. JSplitPane is used to divide two
 * (and only two) Components. This class intend to manipulate the JSplitPane in
 * a way that can be placed as many Component as wanted.
 * 
 * @author Bode
 *
 */
public class JSplitPaneMultiTabs extends JSplitPane {
    private ArrayList<JSplitPane> ecanpsulationList = new ArrayList<JSplitPane>();
    private int numberOfComponents = 1;
    private int sizeOfDivision = 6;

    /**
     * Builds the Pane
     */
    public JSplitPaneMultiTabs() {
        super();
        this.setLeftComponent(null);
        this.setBorder(null);
        ecanpsulationList.add(this);
        setAllBorders(sizeOfDivision);
    }

    /**
     * 
     * @param comp - adds a Component to the Pane
     */
    public void addComponent(Component comp) {
        JSplitPane capsule = new JSplitPane();

        capsule.setRightComponent(null);
        capsule.setLeftComponent(comp);
        capsule.setDividerSize(sizeOfDivision);
        capsule.setBorder(null);

        ecanpsulationList.get(numberOfComponents - 1).setRightComponent(capsule);
        ecanpsulationList.add(capsule);
        numberOfComponents++;
        this.fixWeights();
    }

    /**
     * 
     * @param orientation
     *            JSplitPane.HORIZONTAL_SPLIT - sets the orientation of the
     *            Components to horizontal alignment
     * @param orientation
     *            JSplitPane.VERTICAL_SPLIT - sets the orientation of the
     *            Components to vertical alignment
     */
    public void setAlignment(int orientation) {
        for (int i = 0; i < numberOfComponents; i++) {
            ecanpsulationList.get(i).setOrientation(orientation);

        }
    }

    /**
     * 
     * @param newSize - resizes the borders of the all the Components of the Screen
     */
    public void setAllBorders(int newSize) {
        this.setDividerSize(newSize);
        for (int i = 0; i < numberOfComponents; i++) {
            ecanpsulationList.get(i).setDividerSize(newSize);
        }

    }

    /**
     * each Component added needs to be readapteded to the screen
     */
    private void fixWeights() {
        ecanpsulationList.get(0).setResizeWeight(1.0);
        for (int i = 1; i < numberOfComponents; i++) {
            double resize = (double) 1 / (double) (i + 1);
            ecanpsulationList.get(numberOfComponents - i - 1).setResizeWeight(
                    resize);
        }
        ecanpsulationList.get(numberOfComponents - 1).setResizeWeight(0.0);
    }

}