Java GUI:如何在JFrame上的JPanel中设置对JButton的关注？
Java GUI:如何在JFrame上的JPanel中设置对JButton的关注？
提问于 2011-12-23 20:14:53
我已经进行了实验和搜索，但我似乎想不出什么是我认为简单的事情，那就是当我的小GUI应用程序启动时，让我的开始按钮具有焦点，所以用户所要做的就是按下他们的Enter/Return键，这将具有与他们用鼠标点击开始按钮相同的效果。这是我的代码。感谢您的帮助:)
private void initialize() {
// Launch the frame:
frame = new JFrame();
frame.setTitle("Welcome!");
frame.setSize(520, 480);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Add the image:
ImageIcon heroShotImage = new ImageIcon("heroShot.jpg");
JPanel heroShotPanel = new JPanel();
JLabel heroShot = new JLabel(heroShotImage);
heroShotPanel.add(heroShot);
// Create a panel to hold the "Start" button:
JPanel submitPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
// Create the "Start" button, which launches business logic and dialogs:
JButton start = new JButton("Start");
start.setToolTipText("Click to use library");
start.setFocusable(true); // How do I get focus on button on App launch?
start.requestFocus(true); // Tried a few things and can't get it to work.
// Listen for user actions and do some basic validation:
start.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// THE APP's LOGIC GOES HERE...
}
// Finish setting up the GUI and its components, listeners, and actions:
submitPanel.add(start);
frame.getContentPane().add(heroShotPanel, BorderLayout.NORTH);
frame.getContentPane().add(submitPanel, BorderLayout.SOUTH);
}回答 5
Stack Overflow用户
回答已采纳
发布于 2011-12-23 20:21:29
试试这段代码..我所做的就是在最后移动requestFocus()方法。
基本上，要让它在按enter键时响应，以及在默认情况下将其聚焦，您必须做这两件事。
frame.getRootPane().setDefaultButton(start);
start.requestFocus();
package sof;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class TestFrame {
public static void main(String[] args) {
// Launch the frame:
JFrame frame = new JFrame();
frame.setTitle("Welcome!");
frame.setSize(520, 480);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Add the image:
ImageIcon heroShotImage = new ImageIcon("heroShot.jpg");
JPanel heroShotPanel = new JPanel();
JLabel heroShot = new JLabel(heroShotImage);
heroShotPanel.add(heroShot);
// Create a panel to hold the "Start" button:
JPanel submitPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
JButton start = new JButton("Start");
start.setToolTipText("Click to use library");
start.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("I AM PRESSED");
}
});
submitPanel.add(start);
frame.getContentPane().add(heroShotPanel, BorderLayout.NORTH);
frame.getContentPane().add(submitPanel, BorderLayout.SOUTH);
frame.setVisible(true);
frame.getRootPane().setDefaultButton(start);
start.requestFocus();
}
}Stack Overflow用户
发布于 2011-12-23 20:23:01
如果我理解你，那么你想做一个点击事件的开始按钮，当用户点击回车键。如果是这样的话，你可以这样做：
jFrame.getRootPane().setDefaultButton(start);// 'start' will be your start button如果你只是想在开始按钮上获得焦点，那么在最后(在你使你的框架可见之后)改变你的requestFocus()方法，而不需要在它里面传递true。而且，在java文档中，使用requestFocusInWindow()比使用requestFocus()更好。
Stack Overflow用户
发布于 2011-12-23 20:21:19
将焦点移动到方法的末尾
并将其更改为
start.requestFocus(); // without params页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/8615958
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