Java 如何在jpanel内将jlabel文本向左对齐

Java 如何在jpanel内将jlabel文本向左对齐,java,swing,jpanel,jlabel,layout-manager,Java,Swing,Jpanel,Jlabel,Layout Manager,我正在尝试将Jlabel向左对齐,但是我没有做到。请告诉我如何解决此问题。如果您对此有任何建议,我们将不胜感激 我尝试了这段代码,但它并没有解决问题 Jlabel=new JLabel("Label text",SwingConstants.LEFT); Jlabel.setHorizontalAlignment(SwingConstants.LEFT); 这是我的完整代码 import javax.swing.*; import java.awt.BorderLayout;

我正在尝试将Jlabel向左对齐,但是我没有做到。请告诉我如何解决此问题。如果您对此有任何建议,我们将不胜感激

我尝试了这段代码,但它并没有解决问题

   Jlabel=new JLabel("Label text",SwingConstants.LEFT);
   Jlabel.setHorizontalAlignment(SwingConstants.LEFT);  
这是我的完整代码

import javax.swing.*;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;


public class MyGui1 extends JPanel implements ActionListener {
    /**
     * 
     */
    static JScrollPane jsp;
    protected JPanel panel;
    protected JTextArea textarea;
    static JFrame frame;    
    JLabel Jlabel=null;

    public MyGui1() {
      //to lay out the container's components in a rectangular grid
        super(new GridBagLayout());

        GridBagConstraints c = new GridBagConstraints();
        c.gridwidth = GridBagConstraints.REMAINDER;

        c.fill = GridBagConstraints.HORIZONTAL;

        JButton jbutton=new JButton("button");
        jbutton.setActionCommand("button");
        jbutton.addActionListener(this);
        add(jbutton,c);

        c.gridy=1;
      c.gridwidth = GridBagConstraints.REMAINDER;
        c.fill = GridBagConstraints.BOTH;

        c.weightx = 1.0;
        c.weighty = 1.0;
        setBackground(Color.cyan);
        panel=new JPanel();
        panel.setLayout(new BoxLayout(panel,BoxLayout.PAGE_AXIS));
        jsp=new JScrollPane(panel);

        jsp.setPreferredSize(new Dimension(300,300));

        jsp.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        jsp.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);

        add(jsp, c);
        setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

    }

    public void actionPerformed(ActionEvent evt) {

         if("button".equals(evt.getActionCommand())){
             execute();
         }
    }

   synchronized public void execute(){

            // to remove all the content of panel
            panel.removeAll();
            // to refresh the window

                for(int i=0;i<20 ;i++){


                         Jlabel=new JLabel("Labe1l"+i,SwingConstants.LEFT);

                        // Jlabel.setAlignmentX(CENTER_ALIGNMENT);
                        // Jlabel.setAlignmentY(LEFT_ALIGNMENT);
                         textarea=new JTextArea();
                         textarea.setText("sample text");
                         if(i==2){
                          textarea.setText("sample text........................\nsample text.................. ");
                         }
                       if(i==5){
                          textarea.setText("sample text.\nsample text.sample text.\nsample text. ");
                         }
                     if(i==7){
                          textarea.setText("sample text.\nsample text.sample text.\nsample text sample text..\nsample text.sample text..\nsample text. ");
                         }
                          textarea.append("\n");
                     textarea.setEditable(false);
                        Jlabel.setLayout(new BorderLayout());
                         Jlabel.setHorizontalAlignment(SwingConstants.LEFT);
                       panel.add(Jlabel);

                           // in order to wrap up the data in text area
                           textarea.setLineWrap(true);
                            panel.add(textarea);   
                           Jlabel.setPreferredSize(new Dimension(240,30));
                           javax.swing.SwingUtilities.invokeLater(new Runnable() {
                               public void run() {
                               //    textarea.setPreferredSize(getMinimumSize());
                                //  panel.setPreferredSize(getSize());
                                panel.revalidate();
                                  panel.repaint();
                                   jsp.getVerticalScrollBar().setValue(0);
                                   jsp.validate();

                               }
                           });

                        } 
                    jsp.revalidate();
                    jsp.repaint();
                    frame.repaint();
                        frame.revalidate();


  }
    @SuppressWarnings("static-access")
    private static void createAndShowGUI() {
        //Create and set up the window.
        frame = new JFrame("DesktopSearchEngine");
        frame.setLayout(new BorderLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //adding window listener for exit operation
        frame.addWindowListener( new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                JFrame frame = (JFrame)e.getSource();

                int result = JOptionPane.showConfirmDialog(
                    frame,
                    "Are you sure you want to exit the application?",
                    "Exit Application",
                    JOptionPane.YES_NO_OPTION);

                if (result == JOptionPane.YES_OPTION)
                    {

                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    }
                else if(result==JOptionPane.NO_OPTION){
                    frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
                }
            }
        });
        //Add contents to the window GUI part and to perform all operations
        frame.add(new MyGui1());

        //Display the window.
        frame.pack();
        //to keep the frame visible 
        frame.setVisible(true);

    }

    public static void main(String[] args) {
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();


            }
        });
    }

    } 
import javax.swing.*;
导入java.awt.BorderLayout;
导入java.awt.Color;
导入java.awt.Dimension;
导入java.awt.GridBagConstraints;
导入java.awt.GridBagLayout;
导入java.awt.GridLayout;
导入java.awt.event.ActionEvent;
导入java.awt.event.ActionListener;
导入java.awt.event.WindowAdapter;
导入java.awt.event.WindowEvent;
公共类MyGui1扩展JPanel实现ActionListener{
/**
* 
*/
静态JScrollPane jsp;
受保护的JPanel面板;
保护区;
静态JFrame;
JLabel JLabel=null;
公共MyGui1(){
//在矩形栅格中布置容器组件的步骤
超级(新GridBagLayout());
GridBagConstraints c=新的GridBagConstraints();
c、 gridwidth=GridBagConstraints.rements;
c、 填充=GridBagConstraints.HORIZONTAL;
JButton JButton=新JButton(“按钮”);
setActionCommand(“按钮”);
addActionListener(这个);
添加(jbutton,c);
c、 gridy=1;
c、 gridwidth=GridBagConstraints.rements;
c、 fill=GridBagConstraints.BOTH;
c、 权重x=1.0;
c、 权重y=1.0;
挫折背景(颜色:青色);
panel=新的JPanel();
panel.setLayout(新的BoxLayout(panel,BoxLayout.PAGE_轴));
jsp=新的JScrollPane(面板);
setPreferredSize(新维度(300300));
setHorizontalScrollBarPolicy(ScrollPaneConstants.HorizontalScrollBar,根据需要);
setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL\u SCROLLBAR\u根据需要);
添加(jsp,c);
setBorder(BorderFactory.createEmptyByOrder(10,10,10,10));
}
已执行的公共无效操作(操作事件evt){
如果(“按钮”.equals(evt.getActionCommand())){
执行();
}
}
同步的公共void execute(){
//要删除面板的所有内容,请执行以下操作:
panel.removeAll();
//刷新窗口

对于(int i=0;i您可以使用
FlowLayout.LEADING将标签包装在
JPanel

JPanel wrapper = new JPanel(new FlowLayout(FlowLayout.LEADING,0, 0));
wrapper.add(Jlabel);
panel.add(wrapper);



还要记住遵循Java命名约定。变量以小写字母开头,使用驼峰式大小写:
Jlabel
jLabel

提供图形用户界面的ASCII艺术(或带有简单图形的图像),它应该以最小的尺寸显示,并且(如果可以调整大小)具有额外的宽度/高度。
jLabel jLabel
使用Java命名约定-
jLabel jLabel
。变量以大写字母开头,使用驼峰大小写。