当表单加载时,我想在文本框中放置一些文字,以指导用户,当用户单击该文本框时,文本将自动删除。
txtEmailId = new JTextField();
txtEmailId.setText("Email ID");
我写了上面的代码,但是当用户点击文本按钮时,它会显示文本并保持原样,我想将其删除。
有没有办法完成这个任务?
当表单加载时,我想在文本框中放置一些文字,以指导用户,当用户单击该文本框时,文本将自动删除。
txtEmailId = new JTextField();
txtEmailId.setText("Email ID");
我曾经重写文本字段的绘制方法,直到最后我拥有了比我想要的更多的自定义文本字段...
后来我找到了这个实用的API,它很简单易用,不需要你去扩展任何组件。它还有一个不错的“buddy”API
现在,这已经被包含在SwingLabs SwingX库中,使它更容易使用...
例如(这使用了SwingX-1.6.4)
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import org.jdesktop.swingx.prompt.PromptSupport;
public class PromptExample {
public static void main(String[] args) {
new PromptExample();
}
public PromptExample() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JTextField bunnies = new JTextField(10);
JTextField ponnies = new JTextField(10);
JTextField unicorns = new JTextField(10);
JTextField fairies = new JTextField(10);
PromptSupport.setPrompt("Bunnies", bunnies);
PromptSupport.setPrompt("Ponnies", ponnies);
PromptSupport.setPrompt("Unicorns", unicorns);
PromptSupport.setPrompt("Fairies", fairies);
PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIDE_PROMPT, bunnies);
PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.HIGHLIGHT_PROMPT, ponnies);
PromptSupport.setFocusBehavior(PromptSupport.FocusBehavior.SHOW_PROMPT, unicorns);
PromptSupport.setFontStyle(Font.BOLD, bunnies);
PromptSupport.setFontStyle(Font.ITALIC, ponnies);
PromptSupport.setFontStyle(Font.ITALIC | Font.BOLD, unicorns);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
frame.add(bunnies, gbc);
frame.add(ponnies, gbc);
frame.add(unicorns, gbc);
frame.add(fairies, gbc);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
JTextField busqueda = new JTextField(20);
add(busqueda);
busqueda.setHorizontalAlignment(SwingConstants.CENTER);
if (busqueda.getText().length() == 0) {
busqueda.setText("Buscar");
busqueda.setForeground(new Color(150, 150, 150));
}
busqueda.addFocusListener(new FocusListener() {
@Override
public void focusGained(FocusEvent e) {
busqueda.setText("");
busqueda.setForeground(new Color(50, 50, 50));
}
@Override
public void focusLost(FocusEvent e) {
if (busqueda.getText().length() == 0) {
busqueda.setText("Buscar");
busqueda.setForeground(new Color(150, 150, 150));
}
}
});