好的，我有一个任务，我们要创建一个泛型对类，然后测试它是否有效。 pair 类有一定的要求必须遵守，但我们可以自由地对测试类做我们想做的事。不可否认，我有点过火了，但这只是因为玩弄想法可以帮助我学习我们在类里面没有涉及的其他东西。现在，我无法展示通用类的内容，因为那部分是作业的重要部分，但至于我的测试类，我将展示所有内容。我试图做到这一点，以便我的第五个文本字段 (tf5) 可以接收用户信息，在按下回车键后，该信息(设置为 ArrayList)是然后发送到我的 JSrollPanel，(myScrollPane)。现在，按照我设置 keylistener 的方式，它会在我输入时将我输入的任何内容添加到文本字段和 JScrollPanel 中。因此，如果我键入 1、2、3、4，我会在面板上打印出 4 个数组列表(每个列表有 1 个数字)。我希望能够在文本字段中键入任何我想要的内容，并且只有在我按下回车键后才将其传递到 JScrollPanel，但对于我来说，我就是无法弄清楚到底该怎么做。谁能帮我解决这个问题？这是我的代码:
package lab10;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.Integer.*;
import java.util.ArrayList;
public class Lab10 extends JFrame {
private Container content;
private JTextField tf1, tf2, tf3, tf4, tf5, tf6;
private JLabel lbl1, lbl2, lbl3, lbl4, lbl5, lbl6, lbl7, lbl8, lbl9, lbl10;
private Font myFont;
private JButton myBtn, myBtn2, tstb;
private JTextArea myTextArea;
private JScrollPane myScrollPane;
private KeyEvent x;
Integer I1, I2;
String S1, S2;
Double D1, D2;
ArrayList A1, A2;
Pair<Integer, Integer> myPairInt = new Pair<>(I1, I2);
Pair<String, Double> myPairStrDbl = new Pair<>(S1, D2);
Pair<ArrayList, String> myPairAryStr = new Pair<>(A1, S2);
public Lab10() {
this(640, 540, "Testing a Generic Pair");
}
public Lab10(int width, int height, String title) {
this.setVisible(true);
this.setTitle(title);
this.setSize(width, height);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
guiComponent();
}
private void guiComponent() {
SpringLayout layout = new SpringLayout();
content = this.getContentPane();
content.setLayout(layout);
myFont = new Font("Magneto", Font.BOLD, 12);
myBtn = new JButton("Do It!");
myBtn2 = new JButton();
myBtn2.setLayout(new BorderLayout());
JLabel label1 = new JLabel("Click here to add elements to Array List");
JLabel label2 = new JLabel("(Before you click the bottom button!)");
myBtn2.add(BorderLayout.NORTH, label1);
myBtn2.add(BorderLayout.SOUTH, label2);
myBtn.addActionListener(new ButtonClick());
myBtn2.addActionListener(new ArrayListClickAdd());
lbl1 = new JLabel("Enter a string of numbers for me to count");
lbl2 = new JLabel("Now enter another string of numbers for me to count");
lbl3 = new JLabel("This is where I show you what you typed ");
lbl4 = new JLabel("Now type a String and I'll count the Ascii sum ");
lbl5 = new JLabel("Now type in a double, i.e. 2.4 or 2.3 or 5.6 ");
lbl6 = new JLabel("This is where I show you what you typed ");
lbl7 = new JLabel("Now Enter an Array List, (just a standard string of numbers) ");
lbl8 = new JLabel("Now Enter a String and I will convert it all to uppercase");
lbl9 = new JLabel("This is where I will show you what you've typed ");
lbl10 = new JLabel();
tf1 = new JTextField(8);
tf2 = new JTextField(8);
tf3 = new JTextField(8);
tf4 = new JTextField(8);
tf5 = new JTextField(8);
tf6 = new JTextField(8);
tf5.addKeyListener(new MyKeyEvent());
myTextArea = new JTextArea();
myTextArea.setColumns(12);
myTextArea.setRows(8);
myTextArea.setFont(myFont);
content.add(lbl1);
layout.putConstraint(SpringLayout.WEST, lbl1, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl1, 10, SpringLayout.NORTH, content);
content.add(tf1);
layout.putConstraint(SpringLayout.WEST, tf1, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, tf1, 10, SpringLayout.SOUTH, lbl1);
content.add(lbl2);
layout.putConstraint(SpringLayout.WEST, lbl2, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl2, 10, SpringLayout.SOUTH, tf1);
content.add(tf2);
layout.putConstraint(SpringLayout.WEST, tf2, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, tf2, 10, SpringLayout.SOUTH, lbl2);
content.add(lbl3);
layout.putConstraint(SpringLayout.WEST, lbl3, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl3, 10, SpringLayout.SOUTH, tf2);
content.add(lbl4);
layout.putConstraint(SpringLayout.WEST, lbl4, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl4, 10, SpringLayout.SOUTH, lbl3);
content.add(tf3);
layout.putConstraint(SpringLayout.WEST, tf3, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, tf3, 10, SpringLayout.SOUTH, lbl4);
content.add(lbl5);
layout.putConstraint(SpringLayout.WEST, lbl5, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl5, 10, SpringLayout.SOUTH, tf3);
content.add(tf4);
layout.putConstraint(SpringLayout.WEST, tf4, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, tf4, 10, SpringLayout.SOUTH, lbl5);
content.add(lbl6);
layout.putConstraint(SpringLayout.WEST, lbl6, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl6, 10, SpringLayout.SOUTH, tf4);
content.add(lbl7);
layout.putConstraint(SpringLayout.WEST, lbl7, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl7, 10, SpringLayout.SOUTH, lbl6);
content.add(tf5);
layout.putConstraint(SpringLayout.WEST, tf5, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, tf5, 10, SpringLayout.SOUTH, lbl7);
content.add(lbl8);
layout.putConstraint(SpringLayout.WEST, lbl8, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl8, 10, SpringLayout.SOUTH, tf5);
content.add(tf6);
layout.putConstraint(SpringLayout.WEST, tf6, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, tf6, 10, SpringLayout.SOUTH, lbl8);
content.add(lbl9);
layout.putConstraint(SpringLayout.WEST, lbl9, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl9, 10, SpringLayout.SOUTH, tf6);
content.add(lbl10);
layout.putConstraint(SpringLayout.WEST, lbl10, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, lbl10, 2, SpringLayout.SOUTH, lbl9);
myScrollPane = new JScrollPane(myTextArea);
content.add(myScrollPane);
layout.putConstraint(SpringLayout.WEST, myScrollPane, 250, SpringLayout.EAST, tf4);
layout.putConstraint(SpringLayout.NORTH, myScrollPane, 1, SpringLayout.SOUTH, myBtn2);
content.add(myBtn2);
layout.putConstraint(SpringLayout.WEST, myBtn2, 3, SpringLayout.EAST, lbl7);
layout.putConstraint(SpringLayout.NORTH, myBtn2, 8, SpringLayout.SOUTH, lbl6);
content.add(myBtn);
layout.putConstraint(SpringLayout.WEST, myBtn, 10, SpringLayout.WEST, content);
layout.putConstraint(SpringLayout.NORTH, myBtn, 10, SpringLayout.SOUTH, lbl10);
}
private String upper(String y) {
return y.toUpperCase();
}
private String getAsciiSum(String z) {
int addSum = 0;
for (int i = 0; i < z.length(); i++) {
char x = z.charAt(i);
int j = (int) x;
addSum += x;
}
z = Integer.toString(addSum);
return z;
}
int sumNums(int x) {
String myNum = Integer.toString(x);
int addSum = 0;
for (int i = 0; i < myNum.length(); i++) {
addSum += Character.digit(myNum.charAt(i), 10);
}
return addSum;
}
int[] getArray(int num) {
String counter = "" + num;
int digits = counter.length();
int[] nums = new int[digits];
for (int i = digits - 1; i >= 0; i--) {
nums[i] = num % 10;
num /= 10;
}
return nums;
}
private class MyKeyEvent implements KeyListener {
public MyKeyEvent() {
}
@Override
public void keyTyped(KeyEvent ke) {
ke.setKeyCode(KeyEvent.VK_RIGHT);
if (ke.getKeyCode() == KeyEvent.VK_RIGHT) {
String arrNum = tf5.getText();
ArrayList arList = new ArrayList();
arList.add(arrNum);
myPairAryStr.setFirst(arList);
myTextArea.append(myPairAryStr.getFirst() + "\n");
tf5.setText("");
}
}
@Override
public void keyPressed(KeyEvent ke) {
}
@Override
public void keyReleased(KeyEvent ke) {
}
}
private class ArrayListClickAdd implements ActionListener {
public ArrayListClickAdd() {
}
@Override
public void actionPerformed(ActionEvent ae) {
String arrNum = tf5.getText();
ArrayList arList = new ArrayList();
arList.add(arrNum);
myPairAryStr.setFirst(arList);
myTextArea.append(myPairAryStr.getFirst() + "\n");
tf5.setText("");
}
}
private class ButtonClick implements ActionListener {
public ButtonClick() {
}
@Override
public void actionPerformed(ActionEvent ae) {
int num = Integer.parseInt(tf1.getText());
int num2 = Integer.parseInt(tf2.getText());
String num3 = tf3.getText();
double num4 = Double.parseDouble(tf4.getText());
String arrLst = tf5.getText();
String num6 = tf6.getText();
int count1 = sumNums(num);
int count2 = sumNums(num2);
String strSum = getAsciiSum(num3);
String goBig = upper(num6);
Integer int1 = new Integer(count1);
Integer int2 = new Integer(count2);
String str1 = strSum;
Double dbl2 = new Double(num4);
ArrayList arList = new ArrayList();
arList.add(arrLst);
String str2 = goBig;
myPairInt.setFirst(int1);
myPairInt.setSecond(int2);
myPairStrDbl.setFirst(str1);
myPairStrDbl.setSecond(dbl2);
myPairAryStr.setFirst(arList);
myPairAryStr.setSecond(str2);
lbl3.setText("Your numbers fromthe first field add up to : " + myPairInt.getFirst() + " and your numbers from the second field add up to : " + myPairInt.getSecond());
lbl6.setText("The Ascii sum of the first Field is : " + myPairStrDbl.getFirst() + " and you typed : " + myPairStrDbl.getSecond() + " In the Second Field");
lbl9.setText("You typed : " + myPairAryStr.getFirst() + " In the first Field,");
lbl10.setText("and : " + myPairAryStr.getSecond() + " In the Second");
myTextArea.append(myPairAryStr.getFirst() + "\n");
}
}
public static void main(String[] args) {
Lab10 test = new Lab10();
}
最佳答案
先看看 How to use textfields .
基本上，您想在文本字段上注册一个ActionListener，当用户按下Enter 键时会收到通知
看看How to write Action Listeners了解更多详情。
您应该避免使用 KeyListener，使用 DocumentListener 来监视对基础文档的更改，或者使用 DocumentFilter 如果您想过滤什么正在输入。参见 Using Text Components了解更多详情
关于java - 如何使键事件与单个文本字段一起工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19676129/