我正在使用JButtons和JTextFields制作一个程序。 ActionListeners适用于JButtons,但不适用于JTextFields。
public class Gui extends JFrame {
private JButton Subject[] = new JButton[8];
private String SubjNames[] = {"Length", "Mass", "Currency", "Temperature", "Time", "Speed", "Data", "Cooking"};
private JButton Length1[] = new JButton[8];
private JButton Length2[] = new JButton[8];
private String LengNames[] = {"inches", "feet", "yards", "miles", "millimeters", "centimeters", "meters", "kilometers"};
private JTextField convertedFrom;
private JTextField amountFrom;
private JTextField convertedTo;
private JTextField amountTo;
private String from;
private String CTo;
private String ATo;
private int SubjectLocX = 40;
private int SubjectLocY = 50;
private int Length1LocX = 40;
private int Length1LocY = 150;
private int Length2LocX = 330;
private int Length2LocY = 150;
private int t = 0;
public Gui (){
super("Converter");
setLayout(null);
System.out.println("yes");
for (int i = 0; i<8; i++) {
Subject[i] = new JButton(SubjNames[i]);
Subject[i].setLocation(SubjectLocX,SubjectLocY);
Subject[i].setSize(200,50);
add(Subject[i]);
if (i < 3) {
SubjectLocX = 40;
SubjectLocY += 100;
} else if (i == 3) {
SubjectLocX = 330;
SubjectLocY = 50;
} else if (i > 3) {
SubjectLocY += 100;
}
}
HandlerClass handler = new HandlerClass();
for (int i = 0; i<8; i++) {
Subject[i].addActionListener(handler);
}
for (int i = 0; i<8; i++) {
Length1[i] = new JButton(LengNames[i]);
Length2[i] = new JButton(LengNames[i]);
}
convertedFrom = new JTextField(from, 20);
convertedTo = new JTextField(CTo, 20);
amountFrom = new JTextField("amount", 20);
amountFrom.addActionListener(handler);
amountTo = new JTextField(ATo, 20);
for (int i = 0; i<8; i++) {
Length1[i].addActionListener(handler);
Length2[i].addActionListener(handler);
}
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(600,500);
setLocation(400,200);
setVisible(true);
}
public void Step2() {
for (int i = 0; i<8; i++) {
remove(Subject[i]);
}
for (int i = 0; i<8; i++) {
remove(Length1[i]);
remove(Length2[i]);
}
remove(convertedFrom);
remove(convertedTo);
remove(amountFrom);
remove(amountTo);
HandlerClass handler = new HandlerClass();
convertedFrom = new JTextField(from, 20);
convertedFrom.setEditable(false);
convertedFrom.setLocation(40,50);
convertedFrom.setSize(200,30);
add(convertedFrom);
convertedTo = new JTextField(CTo, 20);
convertedTo.setEditable(false);
convertedTo.setLocation(330,50);
convertedTo.setSize(200,30);
add(convertedTo);
amountFrom = new JTextField("amount", 20);
amountFrom.setLocation(40,100);
amountFrom.setSize(200,30);
add(amountFrom);
amountTo = new JTextField(ATo, 20);
amountTo.setEditable(false);
amountTo.setLocation(330,100);
amountTo.setSize(200,30);
add(amountTo);
Length1LocX = 40;
Length1LocY = 150;
Length2LocX = 330;
Length2LocY = 150;
for (int i = 0; i<8; i++) {
Length1[i].setLocation(Length1LocX, Length1LocY);
Length1[i].setSize(90, 50);
add(Length1[i]);
if (i < 3) {
Length1LocX = 40;
Length1LocY += 100;
} else if (i == 3) {
Length1LocX = 150;
Length1LocY = 150;
} else if (i > 3) {
Length1LocY += 100;
}
Length2[i].setLocation(Length2LocX, Length2LocY);
Length2[i].setSize(90, 50);
add(Length2[i]);
if (i < 3) {
Length2LocX = 330;
Length2LocY += 100;
} else if (i == 3) {
Length2LocX = 440;
Length2LocY = 150;
} else if (i > 3) {
Length2LocY += 100;
}
}
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(600,600);
setLocation(400,200);
setVisible(true);
}
private class HandlerClass implements ActionListener {
public void actionPerformed(ActionEvent event) {
System.out.println("bruhhh");
if (event.getSource() == amountFrom) {
System.out.println("works");
}
for (int i = 0; i<8; i++) {
if (event.getSource() == Length1[i]) {
from = event.getActionCommand();
}
if (event.getSource() == Length2[i]) {
CTo = event.getActionCommand();
}
}
Step2();
}
}
}
在我的Gui构造函数的中间,创建了“amountFrom”TextField,然后我添加了一个actionListener。然后,在ActionHandler类的底部,我查找它的事件。但是,当我运行程序(单击'长度')然后更改数量从文本字段并按回车键,我没有得到控制台打印(假设在textField操作时打印“工作”到控制台发生)。 所有其他Jbutton动作侦听器都可以工作,但是这个textfield actionListener将不起作用。
答案 0 :(得分:1)
在构造函数中,将ActionListener添加到JTextField。
amountFrom = new JTextField("amount", 20);
amountFrom.addActionListener(handler);
但是在你的方法Step2()
中,你创建了一个JTextField的新实例,并且没有为它添加一个监听器。
amountFrom = new JTextField("amount", 20);
amountFrom.setLocation(40,100);
amountFrom.setSize(200,30);
add(amountFrom);
注意:
请查看布局管理器并考虑使用它们。 https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html