Java 保存布局管理器
这个代码不起作用,为什么?Java 保存布局管理器,java,swing,layout-manager,Java,Swing,Layout Manager,这个代码不起作用,为什么? 但是如果我每次都在actionListener中创建一个布局,它就会工作。切换layoutmanager后,只需包括对验证()的调用 import java.awt.LayoutManager; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import jav
但是如果我每次都在actionListener中创建一个布局,它就会工作。切换layoutmanager后,只需包括对
验证()
的调用
import java.awt.LayoutManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class LayoutTest extends JFrame {
public LayoutTest() {
initComponents();
}
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jButton = new JButton();
jPanel1.setBackground(new java.awt.Color(204, 204, 255));
jPanel1.setBorder(javax.swing.BorderFactory.createEtchedBorder());
jButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
LayoutManager tempGroupLayout = jPanel1.getLayout();
jPanel1.setLayout(layoutManager2);
layoutManager = layoutManager2;
layoutManager2 = tempGroupLayout;
}
});
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup().
addContainerGap(286, Short.MAX_VALUE).
addComponent(jButton, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)));
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
addComponent(jButton, javax.swing.GroupLayout.DEFAULT_SIZE, 442, Short.MAX_VALUE));
layoutManager = jPanel1Layout;
javax.swing.GroupLayout jPanel1Layout2 = new javax.swing.GroupLayout(jPanel1);
jPanel1Layout2.setHorizontalGroup(
jPanel1Layout2.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout2.createSequentialGroup().
addComponent(jButton, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)));
jPanel1Layout2.setVerticalGroup(
jPanel1Layout2.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).
addComponent(jButton, javax.swing.GroupLayout.DEFAULT_SIZE, 442, Short.MAX_VALUE));
layoutManager2 = jPanel1Layout2;
getContentPane().add(jPanel1);
pack();
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new LayoutTest().setVisible(true);
}
});
}
private JButton jButton;
private JPanel jPanel1;
private LayoutManager layoutManager;
private LayoutManager layoutManager2;
}
public void actionPerformed(ActionEvent e){
LayoutManager tempGroupLayout=jPanel1.getLayout();
jPanel1.setLayout(layoutManager2);
getContentPane().validate();/@itun“它不工作”是什么意思?它不编译?它不显示按钮?如果单击它不会更改布局?我按了按钮,但它不会更改布局抱歉,我错了。编辑了行(应该是validate而不是invalidate).Ohhh!!非常感谢。我注意到你很有耐心,也不会随口乱说,谢谢。只要注意如果你导入javax.swing.X
你可以直接使用X(例如BorderLayout
而不是javax.swing.BorderLayout
)
public void actionPerformed(ActionEvent e) {
LayoutManager tempGroupLayout = jPanel1.getLayout();
jPanel1.setLayout(layoutManager2);
getContentPane().validate(); // <= added line
layoutManager = layoutManager2;
layoutManager2 = tempGroupLayout;
}