与 JavaFX GUI 事件处理和更新相关的问题

Question

为我的代码长度道歉。我昨晚意识到我走错了路，现在陷入了一个我认为与 JavaFX 事件处理相关的问题。最初，我在 GUI 之外的基本循环中运行逻辑，该循环依赖于通过控制台的交互。一切都很好。我现在尝试让它在用户交互的 GUI 中工作。

我对下面的代码有两个主要问题。

首先是 textArea 中的文本在 startButton 执行我的主逻辑序列的开始后没有更新其他文本。第一个追加从第一个 while 循环的正下方开始。我希望在逻辑执行时将其显示在 GUI 中。我不确定我是否需要告诉 GUI 以一定的时间间隔更新，或者是否有其他问题。

其次，我不确定如何让程序等待用户在 textField 中输入内容，然后再点击我创建的 textButton 继续。我曾经创建了一个扫描仪，导致程序在控制台中等待输入。我意识到我需要某种方式告诉它在 JavaFX 中运行时等待按钮按下。

我选择不包含其余代码以使内容更易于阅读，但如果它有助于解决此问题，我可以添加它。

谢谢大家的帮助！

public class FxApp extends Application {
//Creates FileParser object with methods that alter the incoming Array of Strings into the format we need
FileParser fileParser = new FileParser();
Configure configure = new Configure();
private String text;
private String initialState;
private ArrayList<Machine> machines = new ArrayList<Machine>();
private Map<String, String> initialStates = new HashMap<String, String>();
private Map<String, String> states = new HashMap<String, String>();
private Map<String, ArrayDeque<String>> queues = new HashMap<String, ArrayDeque<String>>();
private Map<Integer, ArrayList<String>> parsedData = new HashMap<Integer, ArrayList<String>>();
@Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setTitle("File Chooser");
FileChooser fileChooser = new FileChooser();
fileChooser.getExtensionFilters().addAll(new ExtensionFilter("Text Files", "*.txt"));
Button startButton = new Button("Start");
Button openButton = new Button("Click to open a file...");
openButton.setPrefSize(200, 80);
Button textButton = new Button("Enter"); 
TextArea textArea = new TextArea();
textArea.setWrapText(true);
TextField textField = new TextField();
Label lbl = new Label();
VBox vbox = new VBox(lbl, openButton, startButton, textArea, textField, textButton);  
vbox.setSpacing(10);
vbox.setPadding(new Insets(15));
lbl.setText("This tool creates virtual automata based ron the file.");
Scene scene = new Scene(vbox, 640, 480);
primaryStage.setScene(scene);
primaryStage.show();  
openButton.setOnAction(
new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent e) {
File file = fileChooser.showOpenDialog(primaryStage);
if (file != null) {
//Execute the method to convert to string array before sending to file parser                           
try {
fileParser.convertFile(file);                           
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
});

textButton.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent event) {
text = textField.getText();                              
}
});
startButton.setOnAction(new EventHandler <ActionEvent>()
{
public void handle(ActionEvent event)
{
machineCreation();
String exit = "no";
String nextLine = null;
ArrayList<String> listOfCurrentTransitions = new ArrayList<String>();
int nextInt = 0;
states = initialStates;
while(!(exit.toLowerCase().equals("yes"))) {
textArea.appendText("Choose a state to load");
//Print out the states possible for each machine
ArrayList<String> tempTrans = machines.get(nextInt).getTransitions();
//This loops through the list of transitions of the machine and pulls possible transitions from its current state
for(int i = 0; i < tempTrans.size(); i++) {
String pull = tempTrans.get(i);
String[] apart = pull.split(" ");
pull = apart[0];
if(states.get(Integer.toString(nextInt)).equals(pull)) {
listOfCurrentTransitions.add(tempTrans.get(i));
}
}
if(!(listOfCurrentTransitions.isEmpty())) {
textArea.appendText("The following transitions are possible. Choose one: " + listOfCurrentTransitions);
}       
else {
textArea.appendText("No transitions for this machine exist from its current state");
}
//Tell GUI to wait for user input in textField and execute textButton which assigns to String text. Resume on button click.

Answer 1

while循环会阻止 JavaFX 应用程序线程，从而阻止 GUI 的更新和事件的处理。

您需要在每个"文本提交"上执行循环的单次迭代逻辑：

private TextArea textArea;
private void activateState(int nextInt) {
ArrayList<String> listOfCurrentTransitions = new ArrayList<String>();
textArea.appendText("Choose a state to load");
//Print out the states possible for each machine
ArrayList<String> tempTrans = machines.get(nextInt).getTransitions();
//This loops through the list of transitions of the machine and pulls possible transitions from its current state
for(int i = 0; i < tempTrans.size(); i++) {
String pull = tempTrans.get(i);
String[] apart = pull.split(" ");
pull = apart[0];
if(states.get(Integer.toString(nextInt)).equals(pull)) {
listOfCurrentTransitions.add(tempTrans.get(i));
}
}
if(listOfCurrentTransitions.isEmpty()) {
textArea.appendText("No transitions for this machine exist from its current state");
} else {
textArea.appendText("The following transitions are possible. Choose one: " + listOfCurrentTransitions);
}
}
@Override
public void start(Stage primaryStage) throws Exception {
...
textArea = new TextArea();
...
startButton.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent event) {
machineCreation();
activateState(0);
}
});
textButton.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent event) {
// read input and ask for more input...
int nextState = Integer.parseInt(textField.getText()); // TODO: deal with invalid input
activateState(nextState);                        
}
});

您可能需要稍微修复一下逻辑以验证转换是否有效，更改某些字段的值等......