带有JDialog的java静态输入对话框

Question

我做了这个样本：

import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;

public class JDialogTest extends JDialog implements ActionListener{
    private boolean actionPerformed;
    private JButton okButton;
    private JTextField textField;

    private JDialogTest(String title, JFrame frame){
        super(frame, title, true);
        setDefaultCloseOperation(HIDE_ON_CLOSE);
        setMinimumSize(new Dimension(200, 200));
        init();
    }

    public static String getInput(String title, JFrame frame){
        JDialogTest input = new JDialogTest(title, frame);
        input.setVisible(true);

        while(true){
            if(input.actionPerformed){
                input.setVisible(false);
                String text = input.textField.getText();
                return text;
            }
        }
    }

    private void init(){

        textField = new JTextField();
        okButton = new JButton("OK");
        okButton.addActionListener(this);

        setLayout(new GridLayout(2, 1, 5, 5));

        add(textField);
        add(okButton);
        pack();     
    }

    @Override
    public void actionPerformed(ActionEvent evt) {
        System.out.println("click");
        actionPerformed = true;     
    }

    public static void main(String[] args) {
        System.out.println(JDialogTest.getInput("Test", null));
    }



}

我通过一个返回字符串的静态方法创建新对话框。 但是while loop witch应该检测到按钮是否被按下，但它不会启动！ 我知道JOptionPanes，但我不想用。我尝试改用JFrame，但如果我尝试在另一个JFrame/JDialog中初始化对话框（它不会渲染），它就不起作用

Answer 1

同样，您需要使用模态JDialog，然后在处理完后查询它所包含的文本。由于对话框是模态的，如果您使对话框在按钮的ActionListener中不可见，则调用应用程序将知道按钮何时被按下。然后将控制权返回给调用程序。然后，调用程序可以通过调用给定的公共方法（这里我称之为getText()）来查询对话框，然后返回对话框的JTextField所包含的字符串

例如，使用你的代码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class JDialogTest extends JDialog implements ActionListener {
   // private boolean actionPerformed;
   private JButton okButton;
   private JTextField textField;

   private JDialogTest(String title, JFrame frame) {
      super(frame, title, true);
      setDefaultCloseOperation(HIDE_ON_CLOSE);
      setMinimumSize(new Dimension(200, 200));
      init();
   }

   // public static String getInput(String title, JFrame frame) {
   // JDialogTest input = new JDialogTest(title, frame);
   // input.setVisible(true);
   //
   // while (true) {
   // if (input.actionPerformed) {
   // input.setVisible(false);
   // String text = input.textField.getText();
   // return text;
   // }
   // }
   // }

   private void init() {

      textField = new JTextField();
      okButton = new JButton("OK");
      okButton.addActionListener(this);

      // UGLY layout
      setLayout(new GridLayout(2, 1, 5, 5));

      add(textField);
      add(okButton);
      pack();
   }

   // I've added this method to allow outside methods to get text
   public String getText() {
      return textField.getText();
   }

   @Override
   public void actionPerformed(ActionEvent evt) {
      System.out.println("click");
      // actionPerformed = true;
      setVisible(false);
   }

   private static void createAndShowGui() {
      final JTextField textField = new JTextField(20);
      JFrame frame = new JFrame("Test JFrame");
      final JDialogTest jDialogTest = new JDialogTest("Dialog", frame);

      JButton button = new JButton(
            new AbstractAction("Press Me to Show Dialog") {
               @Override
               public void actionPerformed(ActionEvent arg0) {
                  jDialogTest.setVisible(true);  // code is frozen here
                                          // until the dialog is no longer visible


                  // when code flow reaches here, we know that the dialog
                  // is no longer visible and 
                  // we now can query our JDialog to get its text
                  textField.setText(jDialogTest.getText());
               }
            });

      textField.setFocusable(false);
      JPanel panel = new JPanel();
      panel.add(button);
      panel.add(textField);

      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(panel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

---

编辑

如果希望以静态方式显示对话框，请将getInput方法更改为：

public static String getInput(String title, JFrame frame) {
  JDialogTest input = new JDialogTest(title, frame);

  input.setVisible(true);

  return input.getText();
}

---

呼叫代码的更改：

  final JTextField textField = new JTextField(20);
  final JFrame frame = new JFrame("Test JFrame");

  JButton button = new JButton(
        new AbstractAction("Press Me to Show Dialog") {
           @Override
           public void actionPerformed(ActionEvent arg0) {                  
              String result = JDialogTest.getInput("Get Input", frame);
              textField.setText(result);
           }
        });

---

编辑2

请注意，JOptionPane的效果非常好：

String result = JOptionPane.showInputDialog(frame, "Please enter input:", 
      "Get Input", JOptionPane.PLAIN_MESSAGE);

---

编辑3
你问：

The solution in the edit seems to work but what method should I use in the action listener to close the JDialog and return the text?

对话框按钮的ActionListener将通过调用setVisible(false)或dispose()使对话框不可见。请参阅上面的我的代码或nachokk的代码以获取示例

Answer 2

这里有一个可能的解决方案。特别注意JDialogTest构造函数getInput()和actionPerformed()的更改

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class JDialogTest extends JDialog implements ActionListener{
    private JButton okButton;
    private JTextField textField;

    private JDialogTest(String title, JFrame frame){
        super(frame, title, true);
        this.setModal(true);                   // Set the dialog as modal
        setDefaultCloseOperation(HIDE_ON_CLOSE);
        setMinimumSize(new Dimension(200, 200));
        init();
    }

    public static String getInput(String title, JFrame frame){
        JDialogTest input = new JDialogTest(title, frame);
        input.setVisible(true);
        return input.textField.getText();       // If this is executed, the dialog box has closed
    }

    private void init(){

        textField = new JTextField();
        okButton = new JButton("OK");
        okButton.addActionListener(this);

        setLayout(new GridLayout(2, 1, 5, 5));

        add(textField);
        add(okButton);
        pack();     
    }

    @Override
    public void actionPerformed(ActionEvent evt) {
        System.out.println("click");
        setVisible(false);             // Close the modal dialog box  
    }

    public static void main(String[] args) {
        System.out.println(JDialogTest.getInput("Test", null));
    }
}

Answer 3

当while(true)与gui在同一线程中运行时，将冻结您的视图，这不是您使用侦听器的正确方式。由于对话框是模态的，因此该对话框具有流控制

在你的例子中，看看这个基于SSCCE的，有一些变化

例如：

public class JDialogTest {

    private JDialog dialog;
    private JTextField textField;

private JDialogTest (String title, JFrame frame){
    dialog = new JDialog(frame, title, true);
    dialog.setDefaultCloseOperation(JDialog.HIDE_ON_CLOSE);
    dialog.setMinimumSize(new Dimension(200, 200));
    init();
}

public void setVisible(Boolean flag){
    dialog.setVisible(flag);
}

public static String getInput(String title, JFrame frame){
    JDialogTest input = new JDialogTest (title, frame);
    input.setVisible(true);
    String text = input.textField.getText();
    return text;
}

private void init(){

    textField = new JTextField();
    JButton okButton = new JButton("OK");
    okButton.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent e) {
                dialog.dispose();
            }

    });

    dialog.setLayout(new GridLayout(2, 1, 5, 5));

    dialog.add(textField);
    dialog.add(okButton);
    dialog.pack();     
}

public static void main(String args []){
    String s = getInput("Dialog",null);
    System.out.println(s);
}


}