Question

请考虑以下代码。

import edu.cmu.ri.createlab.terk.robot.finch.Finch;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class RobotControl extends JFrame {
   public static void main (String args[])  {

    RobotControl GUI = new RobotControl();
    GUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    GUI.setSize(500,500);
    GUI.setVisible(true);
    GUI.setTitle("RobotControl");
}

//The following are declarations of object variables.
    private Finch myf;
    private JButton front;
    private JButton back;
    private JButton left;


public RobotControl() { 
    myf = new Finch();
    setLayout (new FlowLayout());


    front = new JButton("front");
    add(front);
    front.addActionListener(new FrontButtonListener(myf));
    back = new JButton("back");
    add(back);
    back.addActionListener(new BackButtonListener(myf));
    left = new JButton("left");
    add(left);
    left.addActionListener(new LeftButtonListener(myf));

    }
public class FrontButtonListener implements ActionListener {
    public FrontButtonListener(Finch myf) {
        // TODO Auto-generated constructor stub
    }
                public void actionPerformed(ActionEvent arg0) {
                    myf.setWheelVelocities(100,100,10000);
                }
    }
public class BackButtonListener implements ActionListener{
    public BackButtonListener(Finch myf){   
    }
                public void actionPerformed(ActionEvent arg0) {
                    myf.setWheelVelocities(-100,-100,10000);
                }
    }   
public class LeftButtonListener implements ActionListener{
    public LeftButtonListener(Finch myf){
    }
                public void actionPerformed(ActionEvent arg0){
                    myf.setWheelVelocities(0, 200, 1000);
                }

现在，上面的代码将创建一个GUI，有三个按钮，前面，后面和左边。我需要一些建议，让程序在运行之前等待所有三个按钮被点击，而不是一次点击一个按钮。

Answer 1

为每个boolean创建一个button变量，在点击其对应按钮时将其设置为true 。

private  boolean  firstClicked = false;
private  boolean  secondClicked = false;
private  boolean  thirdClicked = false;
......
......
//set these boolean values in their onClick actionPerfomed method
if(firstClicked && secondClicked && thirdClicked){
//do whatever operations you want after three buttons have been clicked
}

注意：您需要在Class级别

中拥有这些布尔变量

Answer 2

使用JToggleButton或JCheckBox保留每个按钮的状态。假设List<JToggleButton>名为list，您可以按如下方式计算allTrue谓词：

boolean allTrue = true;
for (JToggleButton b : list) {
    allTrue &= b.getSelected;
}

仅在allTrue为true时启用所需功能。我们看到了一个相关的例子here。

Answer 3

跟踪已经点击的数量（使用int）。要执行此操作，请仅在单击尚未单击的按钮时递增int（您可以使用boolean跟踪此情况）。当int等于3时，无论单击按钮的顺序如何，请调用外部方法，该方法执行3 actionPerformed方法中当前的操作。对于左按钮，这样的东西，以及其他类似的东西：

    public void actionPerformed(ActionEvent arg0) {
        if(!leftClicked) {
            leftClicked = true;
            numButtonsClicked++;
        }
        countLeftButtonClicks++;
        if(numButtonsClicked == 3) {
            newMethodThatWritesToLogFileToo();
        }
    }

在java中操作GUI对象

3 个答案: