请查看以下代码
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
public class GUI extends JFrame
{
private JButton open, process;
private JLabel center;
private JScrollPane scroll;
private Box box;
private IplImage image;
public FirstGUI()
{
open = new JButton("Open Image");
open.setPreferredSize(new Dimension(70,20));
open.setMaximumSize(new Dimension(100,20));
open.addActionListener(new OpenImageAction());
process = new JButton("Process");
process.setPreferredSize(new Dimension(100,20));
process.setMinimumSize(new Dimension(100,20));
process.addActionListener(new ProcessAction());
System.out.println("Open Size: "+open.getSize()+" Process size: "+process.getSize());
box = new Box(BoxLayout.Y_AXIS);
box.add(open);
box.add(process);
center = new JLabel();
scroll = new JScrollPane(center);
getContentPane().add(box,"West");
getContentPane().add(scroll,"Center");
this.setSize(300,300);
this.pack();
this.validate();
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[]args)
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
new GUI();
}
catch(java.lang.Exception e)
{
JOptionPane.showMessageDialog(null,"GUI Error");
}
}
我想让所有按钮的大小相同。在这里，第一个比第二个宽。我需要两个相同的宽度和高度。如您所见，我已经使用了所有可用的setPrefferedSize（），setMaximumSize（），setMinimumSize（），但它仍然无法正常工作。请帮忙！
答案 0 :(得分：9)
以下是使用GridLayout实现此目的的一种方法。我还引入了一个额外的JPanel，以便在JFrame调整大小时按钮不会拉伸，我为它选择了GridBagLayout，以便它将按钮面板垂直居中。肯定有其他方法可以解决您的问题。
您应该尽量避免使用强制首选/最大/最小尺寸。将此委托给L＆amp; F和LayoutMananager's。
如果您在pack()上致电JFrame，则之前设置其大小毫无用处，因为pack()无论如何都会改变它。尝试调用setVisible(true); GUI初始化的最后一行。
如果您想正确理解布局，定位，大小调整等方式如何在Swing中运行，我强烈建议您阅读the tutorial on LayoutManager's。
import java.awt.BorderLayout;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class GUI extends JFrame {
private JButton open, process;
private JLabel center;
private JScrollPane scroll;
private JPanel box;
public GUI() {
open = new JButton("Open Image");
// open.addActionListener(new OpenImageAction());
process = new JButton("Process");
// process.addActionListener(new ProcessAction());
box = new JPanel(new GridLayout(2, 1));
box.add(open);
box.add(process);
JPanel west = new JPanel(new GridBagLayout());
west.add(box);
center = new JLabel("Some center label");
scroll = new JScrollPane(center);
getContentPane().add(west, BorderLayout.WEST);
getContentPane().add(scroll);
this.pack();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (java.lang.Exception e) {
JOptionPane.showMessageDialog(null, "GUI Error");
}
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new GUI();
}
});
}
}
答案 1 :(得分：2)
您可以创建自己的布局管理器来计算所有按钮的最大大小（可能来自首选大小值），并基本上分配相同的大小（通过setSize）。你当然也必须提供位置信息，但这提供了提供垂直和放大的优势。水平布局选项
<强>更新
这是我使用的实现，我不相信它，因为你可以看到它是由Santhosh Kumar撰写的。我发现它非常有用，因为它不仅将所有按钮的尺寸调整为相同的尺寸，而且还提供对齐。您可以在http://www.jroller.com/santhosh/entry/how_do_you_layout_command
找到原始帖子/**
* @author Santhosh Kumar - santhosh@in.fiorano.com
*/
public class ButtonLayout implements LayoutManager, SwingConstants {
protected static Logger logger = Logger.getLogger(ButtonLayout.class);
private int gap;
private int alignment;
public ButtonLayout() {
setAlignment(RIGHT);
setGap(2);
}
public ButtonLayout(int alignment, int gap) {
setGap(gap);
setAlignment(alignment);
}
public ButtonLayout(int gap) {
this(RIGHT, gap);
}
public int getAlignment() {
return alignment;
}
public void setAlignment(int alignment) {
this.alignment = alignment;
}
public int getGap() {
return gap;
}
public void setGap(int gap) {
this.gap = gap;
}
private Dimension[] dimensions(Component children[]) {
int maxWidth = 0;
int maxHeight = 0;
int visibleCount = 0;
Dimension componentPreferredSize;
for (int i = 0, c = children.length; i < c; i++) {
if (children[i].isVisible()) {
componentPreferredSize = children[i].getPreferredSize();
maxWidth = Math.max(maxWidth, componentPreferredSize.width);
maxHeight = Math.max(maxHeight, componentPreferredSize.height);
visibleCount++;
}
}
int usedWidth = 0;
int usedHeight = 0;
switch (alignment) {
case LEFT:
case RIGHT:
usedWidth = maxWidth * visibleCount + gap * (visibleCount - 1);
usedHeight = maxHeight;
break;
case TOP:
case BOTTOM:
usedWidth = maxWidth;
usedHeight = maxHeight * visibleCount + gap * (visibleCount - 1);
break;
}
return new Dimension[]{
new Dimension(maxWidth, maxHeight),
new Dimension(usedWidth, usedHeight),};
}
public void layoutContainer(Container container) {
Insets insets = container.getInsets();
int width = container.getWidth() - (insets.left + insets.right);
int height = container.getHeight() - (insets.top + insets.bottom);
Component[] children = container.getComponents();
Dimension dim[] = dimensions(children);
int maxWidth = dim[0].width;
int maxHeight = dim[0].height;
int usedWidth = dim[1].width;
int usedHeight = dim[1].height;
for (int i = 0, c = children.length; i < c; i++) {
if (children[i].isVisible()) {
switch (alignment) {
case LEFT:
children[i].setBounds(
insets.left + (maxWidth + gap) * i,
insets.top,
maxWidth,
maxHeight);
break;
case TOP:
children[i].setBounds(
insets.left + ((width - maxWidth) / 2),
insets.top + (maxHeight + gap) * i,
maxWidth,
maxHeight);
break;
case RIGHT:
children[i].setBounds(
width - insets.right - usedWidth + (maxWidth + gap) * i,
insets.top,
maxWidth,
maxHeight);
break;
case BOTTOM:
children[i].setBounds(
insets.left + (maxWidth + gap) * i,
height - insets.bottom - usedHeight + (maxHeight + gap) * i,
// insets.top,
maxWidth,
maxHeight);
break;
}
}
}
}
public Dimension minimumLayoutSize(Container c) {
return preferredLayoutSize(c);
}
public Dimension preferredLayoutSize(Container container) {
Insets insets = container.getInsets();
Component[] children = container.getComponents();
Dimension dim[] = dimensions(children);
int usedWidth = dim[1].width;
int usedHeight = dim[1].height;
return new Dimension(
insets.left + usedWidth + insets.right,
insets.top + usedHeight + insets.bottom);
}
public void addLayoutComponent(String string, Component comp) {
}
public void removeLayoutComponent(Component c) {
}
}
答案 2 :(得分：-1)
答案 3 :(得分：-2)
也许是因为setPreferredSize()的维度不一样了？
open.setPreferredSize(new Dimension(70,20));
process.setPreferredSize(new Dimension(100,20));