当面板已满时,将scrollpane添加到jpanel(java)
我正在开发java swing应用程序,并在当面板已满时,将scrollpane添加到jpanel(java),java,swing,jpanel,jscrollpane,Java,Swing,Jpanel,Jscrollpane,我正在开发java swing应用程序,并在JPanel中动态添加组件。我想在此面板上设置一个JScrollPane,只有当面板已满时,我们才能看到此滚动窗格 我怎样才能在这方面做到: package add_button; import java.awt.Dimension; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.Insets; import java.awt.ev
JPanel
中动态添加组件。我想在此面板上设置一个JScrollPane
,只有当面板已满时,我们才能看到此滚动窗格
我怎样才能在这方面做到:
package add_button;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.LineBorder;
public class MyExample
{
// Field members
static JPanel panel = new JPanel();
static Integer indexer = 1;
static List<JLabel> listOfLabels = new ArrayList<JLabel>();
static List<JTextField> listOfTextFields = new ArrayList<JTextField>();
public static void main(String[] args)
{
// Construct frame
JFrame frame = new JFrame();
frame.setLayout(new GridBagLayout());
frame.setPreferredSize(new Dimension(990, 990));
frame.setTitle("My Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Frame constraints
GridBagConstraints frameConstraints = new GridBagConstraints();
// Construct button
JButton addButton = new JButton("Add");
addButton.addActionListener(new ButtonListener());
// Add button to frame
frameConstraints.gridx = 0;
frameConstraints.gridy = 0;
frame.add(addButton, frameConstraints);
// Construct panel
panel.setPreferredSize(new Dimension(600, 600));
panel.setLayout(new GridBagLayout());
panel.setBorder(LineBorder.createBlackLineBorder());
// Add panel to frame
frameConstraints.gridx = 0;
frameConstraints.gridy = 1;
frameConstraints.weighty = 1;
frame.add(panel, frameConstraints);
// Pack frame
frame.pack();
// Make frame visible
frame.setVisible(true);
}
static class ButtonListener implements ActionListener
{
@Override
public void actionPerformed(ActionEvent arg0)
{
// Clear panel
panel.removeAll();
// Create label and text field
JTextField jTextField = new JTextField();
jTextField.setSize(100, 200);
listOfTextFields.add(jTextField);
listOfLabels.add(new JLabel("Label " + indexer));
// Create constraints
GridBagConstraints textFieldConstraints = new GridBagConstraints();
GridBagConstraints labelConstraints = new GridBagConstraints();
// Add labels and text fields
for(int i = 0; i < indexer; i++)
{
// Text field constraints
textFieldConstraints.gridx = 1;
textFieldConstraints.fill = GridBagConstraints.HORIZONTAL;
textFieldConstraints.weightx = 0.5;
textFieldConstraints.insets = new Insets(10, 10, 10, 10);
textFieldConstraints.gridy = i;
// Label constraints
labelConstraints.gridx = 0;
labelConstraints.gridy = i;
labelConstraints.insets = new Insets(10, 10, 10, 10);
// Add them to panel
panel.add(listOfLabels.get(i), labelConstraints);
panel.add(listOfTextFields.get(i), textFieldConstraints);
}
// Align components top-to-bottom
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = indexer;
c.weighty = 1;
panel.add(new JLabel(), c);
// Increment indexer
indexer++;
panel.updateUI();
}
}
}
包添加按钮;
导入java.awt.Dimension;
导入java.awt.GridBagConstraints;
导入java.awt.GridBagLayout;
导入java.awt.Insets;
导入java.awt.event.ActionEvent;
导入java.awt.event.ActionListener;
导入java.util.ArrayList;
导入java.util.List;
导入javax.swing.JButton;
导入javax.swing.JFrame;
导入javax.swing.JLabel;
导入javax.swing.JPanel;
导入javax.swing.JTextField;
导入javax.swing.border.LineBorder;
公共类MyExample
{
//现场成员
静态JPanel面板=新JPanel();
静态整数索引器=1;
静态列表listOfLabels=newArrayList();
静态列表listOfTextFields=new ArrayList();
公共静态void main(字符串[]args)
{
//构造框架
JFrame=新JFrame();
frame.setLayout(新的GridBagLayout());
frame.setPreferredSize(新尺寸(990990));
frame.setTitle(“我的示例”);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//框架约束
GridBagConstraints frameConstraints=新的GridBagConstraints();
//构造按钮
JButton addButton=新JButton(“添加”);
addButton.addActionListener(newButtonListener());
//将按钮添加到框架
frameConstraints.gridx=0;
frameConstraints.gridy=0;
添加(addButton,frameConstraints);
//构造面板
面板。设置首选尺寸(新尺寸(600600));
panel.setLayout(新的GridBagLayout());
panel.setOrder(LineBorder.createBlackLineBorder());
//将面板添加到框架
frameConstraints.gridx=0;
frameConstraints.gridy=1;
frameConstraints.weighty=1;
添加(面板、框架约束);
//包装架
frame.pack();
//使框架可见
frame.setVisible(true);
}
静态类ButtonListener实现ActionListener
{
@凌驾
已执行的公共无效操作(操作事件arg0)
{
//透明面板
panel.removeAll();
//创建标签和文本字段
JTextField JTextField=新的JTextField();
jTextField.setSize(100200);
添加(jTextField);
添加(新的JLabel(“标签”+索引器));
//创建约束
GridBagConstraints textFieldConstraints=新的GridBagConstraints();
GridBagConstraints labelConstraints=新的GridBagConstraints();
//添加标签和文本字段
for(int i=0;i
将面板添加到JScrollPane中,但由该构造函数创建滚动窗格
JScrollPane scrollPane=新的JScrollPane(面板,ScrollPaneConstants.VERTICAL\u SCROLLBAR\u AS\u NEEDED,ScrollPaneConstants.HORIZONTAL\u SCROLLBAR\u NEEDED
)
只有当面板尺寸大于父组件尺寸时,滚动条才可见。在jscrollpane上,您需要设置垂直和水平条方案。比如说
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
public class windows_test {
JFrame login = null;
JFrame inner_frame = null;
public windows_test() {
login = new JFrame();
login.setBounds(10, 10, 300, 300);
login.setLayout(new BorderLayout());
JPanel temp_panel = new JPanel();
temp_panel.add(new JTextArea("asd fsj adhf jsad kjfh sa dj kfh j sak ds fda f hsa kj d hf ks ad hf kjs ad h fk js ad h fjs da hf k j sahd kjfsh d jk fhs ad"));
login.setVisible(true);
JScrollPane scroll_pane = new JScrollPane(temp_panel);
scroll_pane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED); //SETTING SCHEME FOR HORIZONTAL BAR
scroll_pane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
login.add(scroll_pane);
}
}
希望它能帮助你。如果你遇到任何问题,你可以问我,我会尽力解决。给你
// Construct panel
//panel.setPreferredSize(new Dimension(600, 600)); // No need for panel as it will get added to scrollpane
panel.setLayout(new GridBagLayout());
panel.setBorder(LineBorder.createBlackLineBorder());
JScrollPane scrollPane = new JScrollPane(panel, ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
scrollPane.setPreferredSize(new Dimension(600, 600));
// Add panel to frame
frameConstraints.gridx = 0;
frameConstraints.gridy = 1;
frameConstraints.weighty = 1;
frame.add(scrollPane, frameConstraints); // add acrollpane to frame
我创建了一个,添加了面板
作为其组件,然后将滚动窗格
添加到框架
这里
这段代码通常用于将JScrollPane添加到JPanel。根据您的要求调整框架、面板和滚动窗格的边界,但确保JScrollPane的边界在框架的边界内,否则滚动窗格将不可见。您看到了什么?滚动条立即出现?是否将JScrollPane添加到框架中?请参阅下面的答案。a)永远不要调用setXXSize:b)不要在应用程序代码中使用updateUI c)不要使用setSize:定位和调整大小是LayoutManager(在您的情况下是GridBag)的唯一任务,调用无效不要使用setXXSize-甚至在滚动窗格上也不要使用:-),使用满足您需要的LayoutManager和/或让面板实现Scrollable,根据其内容返回prefScrollableViewportSize提示。@kleopatra明白了,我以后会处理这个问题,感谢您分享这一宝贵的知识。
frame = new JFrame();
frame.setBounds(0, 0, 820, 950);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JPanel panel = new JPanel();
panel.setLayout(null);
final JScrollPane scrollPanel = new JScrollPane(
panel,
ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS
);
scrollPanel.setBounds(0, 0, 800, 900);
panel.setBounds(0, 0, 1920, 1080);
panel.setPreferredSize(new Dimension(1920, 1080));
frame.getContentPane().add(scrollPanel);