如何在Java jPanel上打印一些文本？
对某些人来说，这可能是一个非常明显的问题，但我无法理解。我是Eclipse新手，只使用Dr.Java编程。 我正在创建一个mad libs程序，用户必须输入名词、形容词、名称、数字，最后它会在故事中显示出来 在用户输入了所有必需的信息后，我希望在jPanel中打开完成的故事。我不知道如何将文本添加到jPanel。（我希望在用户输入所有信息后，以c.代码开头的文本显示在窗口中） 代码如下：如何在Java jPanel上打印一些文本？,java,swing,jframe,jpanel,Java,Swing,Jframe,Jpanel,对某些人来说，这可能是一个非常明显的问题，但我无法理解。我是Eclipse新手，只使用Dr.Java编程。 我正在创建一个mad libs程序，用户必须输入名词、形容词、名称、数字，最后它会在故事中显示出来 在用户输入了所有必需的信息后，我希望在jPanel中打开完成的故事。我不知道如何将文本添加到jPanel。（我希望在用户输入所有信息后，以c.代码开头的文本显示在窗口中） 代码如下： import java.util.Scanner; import java.awt.*; import
import java.util.Scanner;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MadLibs{
public static void Action1 ()
{
JFrame frame = new JFrame("Mad Libs");
// Add a window listener for close button
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Scanner input = new Scanner(System.in);
System.out.println("Male Friend:");
String maleFriend = input.nextLine();
System.out.println("Adjective:");
String adjective1 = input.nextLine();
System.out.println("Past Tense Verb:");
String pastTenseVerb1 = input.nextLine();
System.out.println("Past Tense Verb 2:");
String pastTenseVerb2 = input.nextLine();
System.out.println("Large Number:");
String largeNumber = input.nextLine();
System.out.println("Famous Female:");
String famousFemale = input.nextLine();
System.out.println("Adverb:");
String adverb = input.nextLine();
System.out.println("Place:");
String place = input.nextLine();
System.out.println("Body Part(singular):");
String bodyPart = input.nextLine();
System.out.println("Large Number:");
String largeNumber2 = input.nextLine();
System.out.println("Verb ending with -ing");
String ingEnding1 = input.nextLine();
System.out.println("Singular noun:");
String singularNoun = input.nextLine();
System.out.println("Plural Noun:");
String pluralNoun = input.nextLine();
// This is an empty content area in the frame
JLabel jlbempty = new JLabel("");
jlbempty.setPreferredSize(new Dimension(600, 800));
frame.getContentPane().add(jlbempty, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
//The story I want displayed on the jPanel:
/*
c.println("The Great Dough Disaster");
c.println("\nLast summer, my friend "+ maleFriend + " got a job at the " + adjective1 +" Pastry Shop. For the first few");
c.println("weeks, he " + pastTenseVerb1 + " the floors, " + pastTenseVerb2 + " on the shelves, and unloaded " + largeNumber + " pound sacks");
c.println("of flour from the delivery trucks.\n");
c.println("Finally, "+famousFemale+", the owner, told "+maleFriend+" that she would teach him to make bread. Now,");
c.println("pay attention, "+maleFriend+",” she said every day. “I'll make the first batch of dough. Then you");
c.println("can make the next batch while I go to "+place+".\n");
c.println("Poor "+maleFriend+"! He had a habit of letting his "+bodyPart+" wander. When " +famousFemale+ " left for "+place);
c.println("he started to mix the ingredients. “Let me see,” he said. “I think she put in "+largeNumber2);
c.println("packages of yeast.”\n");
c.println("A short while later, the dough started "+ingEnding1+". It kept on "+ingEnding1+". "+maleFriend+" tried to");
c.println("cover it with a(n) "+singularNoun+", but the dough wouldn't stop "+ingEnding1+". It was everywhere! ");
c.println("“What can I do?” thought "+maleFriend+".\n");
c.println("Just then, Tyana returned from toronto. “"+maleFriend+"” she screamed. “What have you done?”");
c.println("“It's not my fault,” cried "+maleFriend+". “The dough just started "+ingEnding1+" and wouldn't stop.”");
c.println(famousFemale + " had to let him go. Now "+maleFriend+" has a job making "+singularNoun+". I don't think he'll ever");
c.print("eat bread again, let alone make it.");
*/
}
public static void main(String []args){
Action1();
}
}
另外，我对jPanel的工作原理有点困惑。我找到了很多在jPanel上显示东西的方法，但我不知道该用哪一种 我马上想到了两种方法 第一种方法要简单得多，即使用paintComponent（图形）方法。每当程序认为需要重新绘制对象时，就会自动调用此方法，例如最小化和ERMM取消最小化保存jpanel的窗口 下面是一个简单的例子
import javax.swing.JPanel;
import java.awt.Graphics;
import java.lang.Override; //for @Override
class yourClass extends JPanel { //yourClass is the JPanel
@Override //if you aren't overriding correctly this makes the compiler tell you
protected void paintComponent(Graphics gr){
super.paintComponent(gr);
gr.drawString("string literal or a string variable", 0,10);
}
}
import java.awt.GridLayout;
import java.awt.Graphics;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JFrame;
import java.lang.Override;
class YourMainClass {
static JFrame mainFrame;
static YourJLabel clsLabel;
static JPanel pnlJPanel;
public static void main(String[]args){
mainFrame = new JFrame("Testing"); //initialize, and set size the frame
mainFrame.setSize(500,500);
pnlJPanel = new JPanel();//initialize our panel
pnlJPanel.setLayout(new GridLayout(3,1));//set its layout to gridlayout, with grid of 3 rows and 1 column
clsLabel = new YourJLabel(); //create a jlabel, add some text to it, then add it to the jpanel
clsLabel.setText("some");
pnlJPanel.add(clsLabel);
clsLabel = new YourJLabel();
clsLabel.setText("Text");
pnlJPanel.add(clsLabel);
clsLabel = new YourJLabel();
clsLabel.setText("drawn");
pnlJPanel.add(clsLabel);
mainFrame.add(pnlJPanel);//add the jpanel to the frame
mainFrame.pack(); //believe you already know these two lines
mainFrame.setVisible(true);
}
}
class YourJLabel extends JLabel {
YourJLabel(){
super();
setOpaque(true); //going on memory, by default jlabels opaque is false, or transparent
}
protected void paintComponent(Graphics gr){
super.paintComponent(gr);
}
}
. Column 1
JPanel.add(JLabel);
import javax.swing.JPanel;
import java.awt.Graphics;
import java.lang.Override; //for @Override
class yourClass extends JPanel { //yourClass is the JPanel
@Override //if you aren't overriding correctly this makes the compiler tell you
protected void paintComponent(Graphics gr){
super.paintComponent(gr);
gr.drawString("string literal or a string variable", 0,10);
}
}
import java.awt.GridLayout;
import java.awt.Graphics;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JFrame;
import java.lang.Override;
class YourMainClass {
static JFrame mainFrame;
static YourJLabel clsLabel;
static JPanel pnlJPanel;
public static void main(String[]args){
mainFrame = new JFrame("Testing"); //initialize, and set size the frame
mainFrame.setSize(500,500);
pnlJPanel = new JPanel();//initialize our panel
pnlJPanel.setLayout(new GridLayout(3,1));//set its layout to gridlayout, with grid of 3 rows and 1 column
clsLabel = new YourJLabel(); //create a jlabel, add some text to it, then add it to the jpanel
clsLabel.setText("some");
pnlJPanel.add(clsLabel);
clsLabel = new YourJLabel();
clsLabel.setText("Text");
pnlJPanel.add(clsLabel);
clsLabel = new YourJLabel();
clsLabel.setText("drawn");
pnlJPanel.add(clsLabel);
mainFrame.add(pnlJPanel);//add the jpanel to the frame
mainFrame.pack(); //believe you already know these two lines
mainFrame.setVisible(true);
}
}
class YourJLabel extends JLabel {
YourJLabel(){
super();
setOpaque(true); //going on memory, by default jlabels opaque is false, or transparent
}
protected void paintComponent(Graphics gr){
super.paintComponent(gr);
}
}
[3]决定了数组的大小，一旦创建了数组，就不能更改它。[]在jLabel上表示您正在创建一个jLabel数组。我立即想到了两种方法 第一种方法要简单得多，即使用paintComponent（图形）方法。每当程序认为需要重新绘制对象时，就会自动调用此方法，例如最小化和ERMM取消最小化保存jpanel的窗口 下面是一个简单的例子
import javax.swing.JPanel;
import java.awt.Graphics;
import java.lang.Override; //for @Override
class yourClass extends JPanel { //yourClass is the JPanel
@Override //if you aren't overriding correctly this makes the compiler tell you
protected void paintComponent(Graphics gr){
super.paintComponent(gr);
gr.drawString("string literal or a string variable", 0,10);
}
}
import java.awt.GridLayout;
import java.awt.Graphics;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JFrame;
import java.lang.Override;
class YourMainClass {
static JFrame mainFrame;
static YourJLabel clsLabel;
static JPanel pnlJPanel;
public static void main(String[]args){
mainFrame = new JFrame("Testing"); //initialize, and set size the frame
mainFrame.setSize(500,500);
pnlJPanel = new JPanel();//initialize our panel
pnlJPanel.setLayout(new GridLayout(3,1));//set its layout to gridlayout, with grid of 3 rows and 1 column
clsLabel = new YourJLabel(); //create a jlabel, add some text to it, then add it to the jpanel
clsLabel.setText("some");
pnlJPanel.add(clsLabel);
clsLabel = new YourJLabel();
clsLabel.setText("Text");
pnlJPanel.add(clsLabel);
clsLabel = new YourJLabel();
clsLabel.setText("drawn");
pnlJPanel.add(clsLabel);
mainFrame.add(pnlJPanel);//add the jpanel to the frame
mainFrame.pack(); //believe you already know these two lines
mainFrame.setVisible(true);
}
}
class YourJLabel extends JLabel {
YourJLabel(){
super();
setOpaque(true); //going on memory, by default jlabels opaque is false, or transparent
}
protected void paintComponent(Graphics gr){
super.paintComponent(gr);
}
}
. Column 1