Java 函数被无故调用两次
我正在申请测验。当我按下视图中的一个键时,模型就会通过控制器更新。但是模型中的函数一开始会被调用一次。下次我按键2次,下次3次,。。。等等 我完全不知道这是怎么发生的。我试过调试它,但没有从多个地方调用它。就从1号开始。这几乎就像关键事件堆积在一起,并不断调用该方法 这是我的多个类的代码 获取关键事件的测验视图:Java 函数被无故调用两次,java,eclipse,debugging,keypress,key-events,Java,Eclipse,Debugging,Keypress,Key Events,我正在申请测验。当我按下视图中的一个键时,模型就会通过控制器更新。但是模型中的函数一开始会被调用一次。下次我按键2次,下次3次,。。。等等 我完全不知道这是怎么发生的。我试过调试它,但没有从多个地方调用它。就从1号开始。这几乎就像关键事件堆积在一起,并不断调用该方法 这是我的多个类的代码 获取关键事件的测验视图: /** * This class will show the questions and react on the keyboard events * @author Matthi
/**
* This class will show the questions and react on the keyboard events
* @author Matthias Claes
*
*/
public class QuizView extends JPanel implements View {
private Observable $model;
private Controller $controller;
private Question $question;
private boolean $isPressed; /* To check if we already listened to a key press event */
public QuizView(Observable model, Controller controller){
setFocusable(true);
$model = model;
if (controller == null)
$controller = new QuizController(model);
else
$controller = controller;
$question = null;
$isPressed = false;
/* Add a keylistener for every team */
addKeyListener(new KeyAdapter() {
public void keyTyped(KeyEvent e) {
int teamSize; /* team size*/
teamSize = ((QuizModel) getModel()).getTeams().size();
if (Character.getNumericValue(e.getKeyChar()) <= teamSize) { /* If you pressed a number under the teamsize we listen to it, and there hasn't been pressed before */
buttonPressed(Character.getNumericValue(e.getKeyChar()));
// Else ignore the key stroke
}
}
});
}
/**
* If a button gets pressed we call this function
* @param team the team that pressed their button
*/
protected void buttonPressed(int team) {
/* Check if a button is pressed */
if(((QuizModel) getModel()).getTeamPressed() > 0)
$isPressed = true;
else
$isPressed = false;
/* If there hasn't been pressed yet and the question is not null */
if(!$isPressed && $question != null){
minimizeFrame(); /* Minimize the frame */
/* If this question has a media path we need to pause the audio/video, we also check if the user has installed vlcplayer and selected the right path */
if($question.getMediaPath() != null && QuizSoftwareModel.$vlcPath != null)
((QuizController)getController()).pause(); /* Pause the video */
/* Give a pop up message to the admin that a team has pushed their button */
((QuizController)getController()).showScoreView(team);
}
}
public void update(Observable arg0, Object arg1) {
$question = (Question) arg1;
System.out.println("CALLED");
if(((QuizModel) getModel()).getMaximize()) /* Only maximize the JFrame when needed */
maximizeFrame(); /* Maximize the frame first */
repaint();
}
/**
* Maximize the parent JFrame so the teams can see the question
*/
protected void maximizeFrame() {
JFrame topFrame = (JFrame) SwingUtilities.getWindowAncestor(this);
topFrame.setState(JFrame.MAXIMIZED_BOTH);
}
/**
* Minimize the parent JFrame so the teams can't see the question anymore
*/
protected void minimizeFrame() {
JFrame topFrame = (JFrame) SwingUtilities.getWindowAncestor(this);
topFrame.setState(JFrame.ICONIFIED);
}
测验模式:
/**
* The model of the quiz
* @author Matthias Claes
*
*/
public class QuizModel extends Observable {
private ArrayList<Question> $questions;
private ArrayList<Team> $teams;
private Question $currentQuestion;
private MediaPlayer $mp;
private int $i; /* The position in the questions, at which question we are at the moment */
private int $teamPressed; /* The team that pressed their button */
private boolean $running;
private boolean $displayScoreView;
private boolean $maximize; /* A boolean that tells the QuizView if we need to maximize this JFrame again */
/**
* Constructor for QuizModel
* @param questions a list of questions
*/
public QuizModel(ArrayList<Question> questions){
$mp = new MediaPlayer(this, null); /* null -> Give the default controller as parameter */
this.addObserver($mp);
$teams = new ArrayList<Team>();
if (questions != null) {
$questions = questions;
}
else
$questions = new ArrayList<Question>();
$currentQuestion = null;
$teamPressed = 0; /* Default value*/
$maximize = false; /* Default value */
$i = 0;
$running = false;
$displayScoreView = false;
}
/**
* Starts the quiz
*/
public void start() {
if (initialized()) {// quiz properly initialized
$running = true;
nextQuestion();
}
else {
// TODO what happens when the quiz isn't properly initialized yet
}
}
/**
* Will create a view where the admin can choose the score if the answer was right, resume if the answer was false.
* @param i the team that pushed the button
*/
public void showScoreView(int i) {
$teamPressed = i;
setDisplayScoreView(true);
/* Update the view */
System.out.println("show score view");
setChanged();
notifyObservers($currentQuestion);
}
/**
* Get the boolean displayScoreView
* @return returns true of false, depending on the displayScoreView boolean
*/
public boolean getDisplayScoreView(){
return $displayScoreView;
}
/**
* Set the $displayScoreView boolean
* @param displayScoreView the new value of $displayScoreView
*/
public void setDisplayScoreView(boolean displayScoreView){
$displayScoreView = displayScoreView;
}
/**
* Goes to the next question in the quiz
*/
public void nextQuestion(){
if($running == true && $i < $questions.size()){
$currentQuestion = $questions.get($i);
$i++;
/* This question has a mediaPath but the user doesn't have vlc installed or selected the wrong folder, so they can't use this question, so we go to the next one */
if($currentQuestion.getMediaPath() != null && QuizSoftwareModel.$vlcPath == null){
JOptionPane.showMessageDialog(null, QuizSoftwareModel.$messages.getString("videoDisplayError"));
nextQuestion(); /* go the next question */
}
/* Display the question */
else{
System.out.println("Diplay first question");
setChanged();
notifyObservers($currentQuestion);
}
} /* End of the quiz */
else{
/* Show winner TODO */
}
}
public Question getCurrentQuestion() {
return $currentQuestion;
}
public int getI() {
return $i;
}
/**
* Resume the question
*/
public void resumeQuestion() {
$teamPressed = 0; /* Reset the team that has pressed so other teams can press aswell */
$maximize = true; /* Maximize the screen again */
$displayScoreView = false;
/* TODO SAVE THE TEAM INTO AN ARRAY SO THIS TEAM CAN'T PRESS AGAIN */
System.out.println("RESUME");
this.setChanged();
this.notifyObservers($currentQuestion);
}
/**
* Return the $maximize boolean
* @return returns the $maximize boolean
*/
public boolean getMaximize() {
return $maximize;
}
}
/**
*测验的模式
*@作者Matthias Claes
*
*/
公共类QuizModel扩展了可观察{
私人ArrayList$问题;
私人ArrayList$团队;
私人问题;私人问题;
私人媒体播放器$mp;
private int$i;/*问题中的位置,即我们目前所处的问题*/
private int$teamPressed;/*按下按钮的团队*/
私有布尔元运行;
私有布尔$displayScoreView;
私有布尔值$maximize;/*一个布尔值,告诉QuizView是否需要再次最大化此JFrame*/
/**
*QuizModel的构造函数
*@param问题一系列问题
*/
公共QuizModel(ArrayList问题){
$mp=new MediaPlayer(这个,null);/*null->将默认控制器作为参数*/
这是一个额外的观察者($mp);
$teams=newarraylist();
如果(问题!=null){
$questions=问题;
}
其他的
$questions=newarraylist();
$currentQuestion=null;
$teamPressed=0;/*默认值*/
$maximize=false;/*默认值*/
$i=0;
$running=false;
$displayScoreView=false;
}
/**
*开始测验
*/
公开作废开始(){
如果(已初始化()){//正确初始化
$running=true;
nextQuestion();
}
否则{
//TODO当测验尚未正确初始化时会发生什么
}
}
/**
*将创建一个视图,管理员可以选择分数,如果答案是正确的,继续如果答案是错误的。
*@param i按下按钮的团队
*/
公共void showScoreView(int i){
$teamPressed=i;
setDisplayScoreView(真);
/*更新视图*/
System.out.println(“显示分数视图”);
setChanged();
通知观察员(当前问题);
}
/**
*获取boolean displayScoreView
*@return返回true或false,具体取决于displayScoreView布尔值
*/
公共布尔getDisplayScoreView(){
返回$displayScoreView;
}
/**
*将$displayScoreView设置为布尔值
*@param displayScoreView$displayScoreView的新值
*/
public void setDisplayScoreView(布尔显示ScoreView){
$displayScoreView=displayScoreView;
}
/**
*转到测验中的下一个问题
*/
public void nextQuestion(){
如果($running==true&&$i<$questions.size()){
$currentQuestion=$questions.get($i);
$i++;
/*此问题有一个mediaPath,但用户没有安装vlc或选择错误的文件夹,因此他们无法使用此问题,因此我们转到下一个问题*/
if($currentQuestion.getMediaPath()!=null&&QuizSoftwareModel.$vlcPath==null){
showMessageDialog(null,QuizSoftwareModel.$messages.getString(“videoDisplayError”);
nextQuestion();/*转到下一个问题*/
}
/*显示问题*/
否则{
System.out.println(“Diplay第一个问题”);
setChanged();
通知观察员(当前问题);
}
}/*测验结束*/
否则{
/*节目赢家托多*/
}
}
公共问题getCurrentQuestion(){
返回$currentQuestion;
}
公共int getI(){
返回$i;
}
/**
*继续提问
*/
公众谘询{
$teamPressed=0;/*重置已按下的团队,以便其他团队也可以按下*/
$maximize=true;/*再次最大化屏幕*/
$displayScoreView=false;
/*TODO将团队保存到数组中,以便此团队不能再次按*/
系统输出打印号(“简历”);
这个.setChanged();
这是一个问题;
}
/**
*返回$maximize布尔值
*@return返回$maximize布尔值
*/
公共布尔getMaximize(){
收益最大化;
}
}
我得到的输出如下:
播放第一个问题
调用
显示分数视图
调用
恢复
调用
显示分数视图
调用
恢复
调用
恢复
调用
因此quizmodel中的resume方法被多次调用 我不知道是否有人能帮我,但已经谢谢了。
很抱歉,我的帖子太长了,但我不知道如何向大家展示它。在方法
displayScoreView()
中,您正在向$resumeButton
引用的按钮添加一个ActionListener
,该按钮最终将调用resumeQuestion()
方法
由于displayScoreView()
是一个实例方法,可以多次调用(似乎会调用),而$resumeButton
在GiveScoreView
实例的整个生命周期中包含同一个按钮实例,因此可能有多个侦听器执行相同的操作(即调用resumeQuestion()
)已在该按钮上注册
请注意,如果很难找出代码实际在做什么,您应该考虑清理它…您正在经历的行为表明,每次程序反应时,您都在向输入添加新的侦听器。尝试移动此代码块:
/* Add actionlisteners to the buttons */
$resumeButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if($question.getMediaPath() != null && QuizSoftwareModel.$vlcPath != null) /* If there is an audio/video piece */
((GiveScoreController)getController()).resumeMP(); /* Resume the mediaplayer if there is an audio/video piece */
((GiveScoreController)getController()).resumeQuestion(); /* Resume the question */
closeFrame(); /* Close the frame */
}
});
$calculateButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if($question.getMediaPath() != null && QuizSoftwareModel.$vlcPath != null) /* If there is an audio/video piece */
((GiveScoreController)getController()).closeMP(); /* Close the mediaplayer */
((GiveScoreController)getController()).nextQuestion(); /* Go on to the next question */
closeFrame(); /* Close the frame */
}
});
要在构造函数内部,请在代码下方执行以下操作:
$resumeButton = new JButton("Resume question"); /* TODO messagebundle */
$calculateButton = new JButton("Calculate score"); /* TODO messagebundle */
这样,您只需为每个按钮创建一个侦听器。为什么要对所有变量名使用
$
?这是非常糟糕的Java风格。这听起来像是调试器非常有用的情况……你会有更好的选择
/* Add actionlisteners to the buttons */
$resumeButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if($question.getMediaPath() != null && QuizSoftwareModel.$vlcPath != null) /* If there is an audio/video piece */
((GiveScoreController)getController()).resumeMP(); /* Resume the mediaplayer if there is an audio/video piece */
((GiveScoreController)getController()).resumeQuestion(); /* Resume the question */
closeFrame(); /* Close the frame */
}
});
$calculateButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if($question.getMediaPath() != null && QuizSoftwareModel.$vlcPath != null) /* If there is an audio/video piece */
((GiveScoreController)getController()).closeMP(); /* Close the mediaplayer */
((GiveScoreController)getController()).nextQuestion(); /* Go on to the next question */
closeFrame(); /* Close the frame */
}
});
$resumeButton = new JButton("Resume question"); /* TODO messagebundle */
$calculateButton = new JButton("Calculate score"); /* TODO messagebundle */