不知道为什么，原生的Swing有JFileChooser，JColorChooser但是却没有JFontChooser。虽然网上有很多类似的实现，但是鉴于是作业，我还是自己写了一个简单的FontChooser来练练手。而且真正写起来也不是那么的顺畅，果然还是发现了很多的坑。。。
功能分析
- 既然是字体选择器，那么至少得能够选择“字体”，“样式”，“大小”。
- 这类的对话框一般得是“阻塞“的，即弹出该对话框后，本来的对话框应该是点不动的直到弹出的对话框结束。
- 仿照JFileChooser和JColorChooser，这类选择工具类的对话框设计为静态的比较好。
- 对话框默认的字体一般是待修改的字体。
- 选择成功得返回选择后的结果，选择退出得返回原先的结果。
实现代码
代码语言：javascript复制import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GraphicsEnvironment;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
public class FontChooser extends JDialog {
private static final long serialVersionUID = 1L;
private static JDialog dlg;
private static Font font, rawFont;
private static JPanel panel;
private static JComboBox<String> comboBoxFont, comboBoxStyle, comboBoxSize;
private static JLabel text;
private static JButton button;
// 向外部提供的静态方法,可阻塞
public static void showDialog(JFrame parent, String title, boolean modal, Font rawfont) {
dlg = new JDialog(parent, title, modal);
rawFont = rawfont;
font = new Font(rawFont.getFontName(), rawFont.getStyle(), rawFont.getSize());
setDefault();
setComboBox();
dlg.setVisible(true);
}
// 获得取得的字体
public static Font getResFont() {
return font;
}
private static void setDefault() {
dlg.setSize(550, 280);
dlg.setTitle("选择字体");
dlg.setResizable(false);
dlg.setLocationRelativeTo(null);
comboBoxFont = new JComboBox<String>();
comboBoxStyle = new JComboBox<String>();
comboBoxSize = new JComboBox<String>();
panel = new JPanel();
dlg.setContentPane(panel);
panel.setLayout(null);
// 关闭窗口，则不更新字体
dlg.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
font = rawFont;
dlg.dispose();
}
});
JPanel panelFont = new JPanel();
panelFont.add(new JLabel("字体:"));
panelFont.add(comboBoxFont);
panel.add(panelFont);
panelFont.setBounds(10, 10, 150, 60);
JPanel panelStyle = new JPanel();
panelStyle.add(new JLabel("风格:"));
panelStyle.add(comboBoxStyle);
panel.add(panelStyle);
panelStyle.setBounds(10, 70, 150, 60);
JPanel panelSize = new JPanel();
panelSize.add(new JLabel("大小:"));
panelSize.add(comboBoxSize);
panel.add(panelSize);
panelSize.setBounds(10, 130, 150, 60);
button = new JButton("确定");
panel.add(button);
button.setBounds(20, 190, 140, 30);
// 点确定，则关闭窗口，保留结果
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
dlg.dispose();
}
});
JPanel panelText = new JPanel();
text = new JLabel();
text.setText("Hello World!");
text.setFont(font);
text.setBorder(BorderFactory.createLoweredBevelBorder());
panelText.setLayout(new BorderLayout());
panelText.add(text);
panelText.setBounds(180, 30, 340, 200);
text.setHorizontalAlignment(SwingConstants.CENTER);
text.setVerticalAlignment(SwingConstants.CENTER);
panel.add(panelText);
}
private static void setComboBox() {
// 获得系统提供的字体
String[] fontnames = GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames();
for (int i = 0; i < fontnames.length; i ) {
comboBoxFont.addItem(fontnames[i]);
}
comboBoxFont.setPreferredSize(new Dimension(100, 30));
comboBoxFont.setSelectedItem(font.getFontName());
comboBoxFont.addItemListener(new ItemListener() {
@Override
public void itemStateChanged(ItemEvent arg0) {
if (arg0.getStateChange() == ItemEvent.SELECTED) {
String s = (String) arg0.getItem();
font = new Font(s, font.getStyle(), font.getSize());
text.setFont(font);
}
}
});
comboBoxStyle.addItem("普通");
comboBoxStyle.addItem("加粗");
comboBoxStyle.addItem("倾斜");
comboBoxStyle.addItem("加粗倾斜");
if (font.getStyle() == Font.BOLD) {
comboBoxStyle.setSelectedItem("加粗");
} else if (font.getStyle() == Font.PLAIN) {
comboBoxStyle.setSelectedItem("普通");
} else if (font.getStyle() == Font.ITALIC) {
comboBoxStyle.setSelectedItem("倾斜");
} else {
comboBoxStyle.setSelectedItem("加粗倾斜");
}
comboBoxStyle.setPreferredSize(new Dimension(100, 30));
comboBoxStyle.addItemListener(new ItemListener() {
@Override
public void itemStateChanged(ItemEvent arg0) {
if (arg0.getStateChange() == ItemEvent.SELECTED) {
String s = (String) arg0.getItem();
if (s.equals("普通")) {
font = new Font(font.getFontName(), Font.PLAIN, font.getSize());
} else if (s.equals("加粗")) {
font = new Font(font.getFontName(), Font.BOLD, font.getSize());
} else if (s.equals("倾斜")) {
font = new Font(font.getFontName(), Font.ITALIC, font.getSize());
} else {
font = new Font(font.getFontName(), Font.BOLD | Font.ITALIC, font.getSize());
}
text.setFont(font);
}
}
});
for (int i = 5; i <= 50; i ) {
comboBoxSize.addItem(i "px");
}
comboBoxSize.setSelectedItem(font.getSize() "px");
comboBoxSize.setPreferredSize(new Dimension(100, 30));
comboBoxSize.addItemListener(new ItemListener() {
@Override
public void itemStateChanged(ItemEvent arg0) {
if (arg0.getStateChange() == ItemEvent.SELECTED) {
String s = (String) arg0.getItem();
s = s.substring(0, s.length() - 2);
font = new Font(font.getFontName(), font.getStyle(), Integer.parseInt(s));
text.setFont(font);
}
}
});
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(720, 540);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
FontChooser.showDialog(frame, "title", true, new Font("宋体", Font.BOLD, 20));
}
}运行截图
