单选按钮事件处理程序

Question

我在 java 项目中遇到了一些问题。我制作了一个空的 GUI 界面，现在我需要为其添加一些功能。但是，我对如何去做感到困惑。基本布局有 4 个单选按钮，Rectangle、Box、Circle 和 Cylinder。我有一个组面板，其中有 4 个单独的面板，每个面板都有带有用于输入高度、长度、宽度和半径的标签的文本框。它的外观如下：GUI layout。根据选择的单选按钮，某些不需要的框应该被隐藏。例如，如果选择了矩形，则只有长度和宽度框应该可见。

显示一切的主框架在这里：

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JButton;
import java.awt.Font;

public class GUIFrame extends JFrame
{
    //private final BorderLayout layout;
    private final FlowLayout layout;
    private final JLabel lblTitle;
    private final JButton btnProc;

    public GUIFrame()
    {

        super("GUI Layout");
        Font titleFont = new Font("Verdana", Font.BOLD, 26);

        btnProc = new JButton("Click to Process");
        lblTitle = new JLabel("Figure Center");
        lblTitle.setFont(titleFont);
        widthPanel myWidth = new widthPanel();
        myWidth.setLocation(0, 400);
        lengthPanel myLength = new lengthPanel();
        heightPanel myHeight = new heightPanel();
        radiusPanel myRadius = new radiusPanel();
        radioButtonPanel myButtons = new radioButtonPanel();

        //layout = new BorderLayout(3, 2);
        layout = new FlowLayout();

        JPanel txtGroup = new JPanel();
        txtGroup.setLayout(new GridLayout(2, 2));
        txtGroup.add(myWidth);
        txtGroup.add(myLength);
        txtGroup.add(myRadius);
        txtGroup.add(myHeight);
        setLayout(layout);

        add(lblTitle);
        add(myButtons);
        add(txtGroup);
        add(btnProc);


        if(myButtons.btnRectangle.isSelected())
        {
            myHeight.setVisible(false);
            myRadius.setVisible(false);
        }

    }

    private class RadioButtonHandler implements ItemListener
    {
        @Override
        public void itemStateChanged(ItemEvent event)
        {

        }
    }

}

我可以使用 if 语句使它工作，但我应该使用事件处理程序，但我不知道如何对其进行编码以使其正常工作。

如果有帮助，这里是按钮面板的代码：

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.ButtonGroup;
import javax.swing.JLabel;
import java.awt.GridLayout;
import java.awt.event.ItemListener;
import java.awt.event.ItemEvent;


public class radioButtonPanel extends JPanel
{
    private final JRadioButton btnRectangle;
    private final JRadioButton btnBox;
    private final JRadioButton btnCircle;
    private final JRadioButton btnCylinder;
    private final ButtonGroup radioButtonGroup;
    private final JLabel label;
    private final JPanel radioPanel;


    public radioButtonPanel()
    {
        radioPanel = new JPanel();
        radioPanel.setLayout(new GridLayout(5,1));

        btnRectangle = new JRadioButton("Rectangle", true);
        btnBox = new JRadioButton("Box", false);
        btnCircle = new JRadioButton("Circle", false);
        btnCylinder = new JRadioButton("Cylinder", false);
        label = new JLabel("Select A Figure:");
        radioPanel.add(label);
        radioPanel.add(btnRectangle);
        radioPanel.add(btnBox);
        radioPanel.add(btnCircle);
        radioPanel.add(btnCylinder);

        radioButtonGroup = new ButtonGroup();
        radioButtonGroup.add(btnRectangle);
        radioButtonGroup.add(btnBox);
        radioButtonGroup.add(btnCircle);
        radioButtonGroup.add(btnCylinder);


        add(radioPanel);


    }

}

以及其中一个面板的样本。它们都遵循相同的设置，只是变量名称不同。

import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JPanel;
import java.awt.GridLayout;

public class heightPanel extends JPanel
{
    private final JLabel lblHeight;
    private final JTextField txtHeight;
    private final JPanel myHeight;

    public heightPanel()
    {
        myHeight = new JPanel();
        myHeight.setLayout(new GridLayout(2,1));

        lblHeight = new JLabel("Enter Height:");
        txtHeight = new JTextField(10);
        myHeight.add(lblHeight);
        myHeight.add(txtHeight);


        add(myHeight);
    }
}

Answer 1

下面的代码可以让您快速了解如何为您的按钮组 (JRadioButtons) 使用事件 listener/handler。

but I'm supposed to be using event handlers and I'm lost on how to code that to get it to work properly.

    //add listener to the rectangle button and should be the same for the other `JRadioButtons` but with different `identifiers`.

    btnRectangle.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
           if(e.getSource() == btnRectangle){
          //TODO
           }
        }
    });

Depending on the radio button that is selected, certain boxes that aren't needed should be hidden. For example, if Rectangle is selected, only the boxes for length and width should be visible.

//要隐藏 JTextFields 使用 void setVisible(boolean visible) 方法。如果要隐藏 JTextField.

，则应将 false 作为参数传递给方法

示例：

 btnRectangle.addActionListener(new ActionListener() {
       @Override
        public void actionPerformed(ActionEvent e) {
           if(e.getSource() == btnRectangle){
              TextFieldName.setVisible(false); // set the textfields that you want to be hidden once the Rectangle button is chosen.
           }
        }
 });

单选按钮事件处理程序

Radio button event handlers

java

eventhandler