java 将值附加到 JTextField？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/28940433/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Append value to JTextField?
提问by Shafiq Fata
I want to append a value into a JTextFieldin Java. Something like:
我想JTextField在 Java 中将一个值附加到 a中。就像是：
String btn1="1";
textField.appendText(btn1);
回答by Duncan Jones
I think you'll find setTextis the answer. Just combine the current value with the new value:
我想你会找到setText答案。只需将当前值与新值结合起来：
textField.setText(textField.getText() + newStringHere);
回答by camickr
If you text field is not editable, you could use:
如果您的文本字段不可编辑，您可以使用：
textField.replaceSelection("...");
If it is editable you might use:
如果它是可编辑的，您可以使用：
textField.setCaretPosition( textField.getDocument().getLength() );
textField.replaceSelection("...");
This would be slightly more efficient (than using setText()) because you are just appending text directly to the Document and would more resemble a JTextArea.append(...).
这会稍微更有效（比使用 setText()），因为您只是将文本直接附加到 Document 并且更类似于 JTextArea.append(...)。
It would only result in a single DocumentEvent - insertUpdate().
它只会导致单个 DocumentEvent - insertUpdate()。
You can also access the Document directly and do the insert:
您还可以直接访问 Document 并进行插入：
Document doc = textField.getDocument();
doc.insertString(...);
but I find this more work because you also have to catch the BadLocationException.
但我发现这更有效，因为您还必须捕获 BadLocationException。
Simple example, that also demonstrate the use of Key Bindings:
简单的例子，也演示了键绑定的使用：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class CalculatorPanel extends JPanel
{
private JTextField display;
public CalculatorPanel()
{
Action numberAction = new AbstractAction()
{
@Override
public void actionPerformed(ActionEvent e)
{
display.replaceSelection(e.getActionCommand());
}
};
setLayout( new BorderLayout() );
display = new JTextField();
display.setEditable( false );
display.setHorizontalAlignment(JTextField.RIGHT);
add(display, BorderLayout.NORTH);
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout( new GridLayout(0, 5) );
add(buttonPanel, BorderLayout.CENTER);
for (int i = 0; i < 10; i++)
{
String text = String.valueOf(i);
JButton button = new JButton( text );
button.addActionListener( numberAction );
button.setBorder( new LineBorder(Color.BLACK) );
button.setPreferredSize( new Dimension(50, 50) );
buttonPanel.add( button );
InputMap inputMap = button.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
inputMap.put(KeyStroke.getKeyStroke(text), text);
inputMap.put(KeyStroke.getKeyStroke("NUMPAD" + text), text);
button.getActionMap().put(text, numberAction);
}
}
private static void createAndShowUI()
{
// UIManager.put("Button.margin", new Insets(10, 10, 10, 10) );
JFrame frame = new JFrame("Calculator Panel");
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.add( new CalculatorPanel() );
frame.pack();
frame.setLocationRelativeTo( null );
frame.setVisible(true);
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
