Java JFrame未被写入
我的JFrame正在打开一个空白窗口。Java JFrame未被写入,java,swing,model-view-controller,jframe,Java,Swing,Model View Controller,Jframe,我的JFrame正在打开一个空白窗口。 我试图创建calcView类的实例,以便打开并写入JFrame窗口,但它没有正常工作。 基本上,我必须使用MVC方法来开发一个只使用乘法运算的计算器,所以这里显示了3个单独的类: CalcView CalcModel import java.awt.event.*; public class CalcModel{ public static final String INITIAL_VALUE = "1"; p
我试图创建calcView类的实例,以便打开并写入JFrame窗口,但它没有正常工作。 基本上,我必须使用MVC方法来开发一个只使用乘法运算的计算器,所以这里显示了3个单独的类:
CalcView CalcModel
import java.awt.event.*;
public class CalcModel{
public static final String INITIAL_VALUE = "1";
public float multiply(){
float i = 0;
return i;
}
}
钙控制器
import javax.swing.*;
public class CalcController {
public static void main(String[] args) {
CalcView v = new CalcView();
v.CalcGUI();
}
public void listener() {
m_clearBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
m_total = new BigInteger(INITIAL_VALUE);
m_totalTf.setText(INITIAL_VALUE);
}
});
m_multiplyBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
CalcModel m = new CalcModel();
m.multiply(e);
} catch (NumberFormatException nex) {
CalcView v = new CalcView();
v.throwExcept();
}
}
});
}
}
此外,如何在类之间传递事件处理程序?
原因是您将内容面板添加到了错误的JFrame。 在这行代码中,您创建了一个新的JFrame
JFrame window = new CalcView();
但是在这些代码行中,您将内容JPanel添加到CalcView类中,而不是它自己
this.setContentPane(content);
this.pack();
有两个选项可以使其可见,第一个选项是不扩展JFrame,并将内容JPanel添加到窗口JFrame。第二个选项是ExtendJFrame,不创建新的窗口JFrame
第一个选项显示在下面的代码中
import javax.swing.*;
import java.math.BigInteger;
import java.awt.*;
public class CalcView{
private static final String INITIAL_VALUE = "1";
private JTextField m_totalTf = new JTextField(10);
private JTextField m_userInputTf = new JTextField(10);
private JButton m_multiplyBtn = new JButton("Multiply");
private JButton m_clearBtn = new JButton("Clear");
private BigInteger m_total; // The total current value state.
JFrame window = new JFrame();
public void CalcGUI() {
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setTitle("Performs Simple Multiplications");
window.setVisible(true);
m_total = new BigInteger(INITIAL_VALUE);
m_totalTf.setText(INITIAL_VALUE);
m_totalTf.setEditable(false);
JPanel content = new JPanel();
content.setLayout(new FlowLayout());
content.add(new JLabel("Input"));
content.add(m_userInputTf);
content.add(m_multiplyBtn);
content.add(new JLabel("Total"));
content.add(m_totalTf);
content.add(m_clearBtn);
window.setContentPane(content);
window.pack();
}
public void throwExcept(){
JOptionPane.showMessageDialog(window, "Bad Number");
}
}
import javax.swing.*;
import java.math.BigInteger;
import java.awt.*;
public class CalcView extends JFrame{
private static final String INITIAL_VALUE = "1";
private JTextField m_totalTf = new JTextField(10);
private JTextField m_userInputTf = new JTextField(10);
private JButton m_multiplyBtn = new JButton("Multiply");
private JButton m_clearBtn = new JButton("Clear");
private BigInteger m_total; // The total current value state.
public void CalcGUI() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Performs Simple Multiplications");
this.setVisible(true);
m_total = new BigInteger(INITIAL_VALUE);
m_totalTf.setText(INITIAL_VALUE);
m_totalTf.setEditable(false);
JPanel content = new JPanel();
content.setLayout(new FlowLayout());
content.add(new JLabel("Input"));
content.add(m_userInputTf);
content.add(m_multiplyBtn);
content.add(new JLabel("Total"));
content.add(m_totalTf);
content.add(m_clearBtn);
this.setContentPane(content);
this.pack();
}
public void throwExcept(){
JOptionPane.showMessageDialog(CalcView.this, "Bad Number");
}
}
第二个选项显示在下面的代码中
import javax.swing.*;
import java.math.BigInteger;
import java.awt.*;
public class CalcView{
private static final String INITIAL_VALUE = "1";
private JTextField m_totalTf = new JTextField(10);
private JTextField m_userInputTf = new JTextField(10);
private JButton m_multiplyBtn = new JButton("Multiply");
private JButton m_clearBtn = new JButton("Clear");
private BigInteger m_total; // The total current value state.
JFrame window = new JFrame();
public void CalcGUI() {
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setTitle("Performs Simple Multiplications");
window.setVisible(true);
m_total = new BigInteger(INITIAL_VALUE);
m_totalTf.setText(INITIAL_VALUE);
m_totalTf.setEditable(false);
JPanel content = new JPanel();
content.setLayout(new FlowLayout());
content.add(new JLabel("Input"));
content.add(m_userInputTf);
content.add(m_multiplyBtn);
content.add(new JLabel("Total"));
content.add(m_totalTf);
content.add(m_clearBtn);
window.setContentPane(content);
window.pack();
}
public void throwExcept(){
JOptionPane.showMessageDialog(window, "Bad Number");
}
}
import javax.swing.*;
import java.math.BigInteger;
import java.awt.*;
public class CalcView extends JFrame{
private static final String INITIAL_VALUE = "1";
private JTextField m_totalTf = new JTextField(10);
private JTextField m_userInputTf = new JTextField(10);
private JButton m_multiplyBtn = new JButton("Multiply");
private JButton m_clearBtn = new JButton("Clear");
private BigInteger m_total; // The total current value state.
public void CalcGUI() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setTitle("Performs Simple Multiplications");
this.setVisible(true);
m_total = new BigInteger(INITIAL_VALUE);
m_totalTf.setText(INITIAL_VALUE);
m_totalTf.setEditable(false);
JPanel content = new JPanel();
content.setLayout(new FlowLayout());
content.add(new JLabel("Input"));
content.add(m_userInputTf);
content.add(m_multiplyBtn);
content.add(new JLabel("Total"));
content.add(m_totalTf);
content.add(m_clearBtn);
this.setContentPane(content);
this.pack();
}
public void throwExcept(){
JOptionPane.showMessageDialog(CalcView.this, "Bad Number");
}
}
此外,您可以使用构造函数在类之间传递事件处理程序,或者只创建一个setter函数。您可以在此处阅读有关构造函数的更多信息。此外,如何在类之间传递事件处理程序每个帖子一个问题。